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Background: Mutations in the dedicator of cytokinesis 8 gene (DOCK8) cause a combined primary immunodeficiency syndrome that is characterized by elevated serum IgE levels, depressed IgM levels, eosinophilia, sinopulmonary infections, cutaneous viral infections, and lymphopenia. Many patients with DOCK8 deficiency were previously thought to have a variant of Job's syndrome. Distinguishing between DOCK8 deficiency and Job's syndrome, also referred to as autosomal dominant hyper- IgE syndrome, on the basis of clinical findings alone is challenging. The discovery of the DOCK8 mutation has made it possible to differentiate the cutaneous manifestations of these hyper-IgE syndromes. Observations: Twenty-one patients from 14 families with confirmed homozygous or compound heterozygous mutations in DOCK8 were evaluated. Clinical findings included dermatitis, asthma, food and environmental allergies, recurrent sinopulmonary infections, staphylococcal skin abscesses, and severe cutaneous viral infections. Malignant neoplasms, including aggressive cutaneous T-cell lymphoma, anal and vulvar squamous cell carcinomas, and diffuse large B-cell lymphoma, developed in 5 patients during adolescence and young adulthood. Conclusions: DOCK8 deficiency and Job's syndrome share several clinical features, including elevated serum IgE levels, dermatitis, recurrent sinopulmonary infections, and cutaneous staphylococcal abscesses. However, the presence of recalcitrant, widespread cutaneous viral infections, asthma, and food and environmental allergies, as well as the absence of newborn rash and coarse facies, favors the clinical diagnosis of DOCK8 deficiency. Rates of malignancy and overall mortality in patients with DOCK8 deficiency were higher than in those with Job's syndrome, highlighting the value of distinguishing between these conditions and the importance of close monitoring for neoplasia. [ABSTRACT FROM AUTHOR]

Grover disease is an acquired epidermal blistering disorder in which keratinocytes lose intercellular connections. While its pathologic features are well defined, its etiology remains unclear, and there is no FDA-approved therapy. Interestingly, Grover disease was a common adverse event in clinical trials for cancer using B-RAF inhibitors, but it remained unknown how B-RAF blockade compromised skin integrity. Here, we identified ERK hyperactivation as a key driver of Grover disease pathology. We leveraged a fluorescent biosensor to confirm that the B-RAF inhibitors dabrafenib and vemurafenib paradoxically activated ERK in human keratinocytes and organotypic epidermis, disrupting cell-cell junctions and weakening epithelial integrity. Consistent with clinical data showing that concomitant MEK blockade prevents Grover disease in patients receiving B-RAF inhibitors, we found that MEK inhibition suppressed ERK and rescued cohesion of B-RAF-inhibited keratinocytes. Validating these results, we demonstrated ERK hyperactivation in patient biopsies from vemurafenib-induced Grover disease and from spontaneous Grover disease, revealing a common etiology for both. Finally, in line with our recent identification of ERK hyperactivation in Darier disease, a genetic disorder with identical pathology to Grover disease, our studies uncovered that the pathogenic mechanisms of these diseases converge on ERK signaling and support MEK inhibition as a therapeutic strategy.

Importance: Germline SUFU pathogenic variants (PVs) have previously been associated with basal cell nevus syndrome (BCNS) and multiple infundibulocystic basal cell carcinoma syndrome; however, a broader spectrum of cutaneous findings in patients with SUFU PVs has not been well delineated., Objective: To define the clinical and histopathologic spectrum of cutaneous findings in patients with germline SUFU PVs., Design, Setting, and Participants: This case series was conducted in multiple US academic dermatology, medical genetics, and medical oncology clinics between July 2014 and July 2022. The study included patients with confirmed germline SUFU PVs who were evaluated by a dermatologist. The analysis took place from March to September 2023., Main Outcomes and Measures: Histopathologic evaluation of skin biopsies with or without immunohistochemical staining, and targeted next-generation sequencing (NGS) on tumor specimens., Results: All 5 patients were women. The mean (range) age at presentation was 50.2 (31-68) years, with skin manifestations initially appearing in the fourth to sixth decades of life. None had keratocystic odontogenic tumors. A total of 29 skin pathology specimens from the 5 patients were reviewed; of these, 3 (10.3%) were diagnosed as basaloid follicular hamartomas (BFHs), 10 (34.5%) classified as infundibulocystic basal cell carcinomas (iBCCs), 6 (20.7%) classified as nodular basal cell carcinomas (nBCCs), and 1 (3.4%) as infiltrative basal cell carcinoma (BCC). Targeted NGS studies on tumor specimens suggest that an increased number of UV-signature variants is associated with basal cell carcinomas compared with more indolent basaloid follicular hamartomas., Conclusions and Relevance: Patients with germline SUFU PVs may present with multiple indolent basaloid neoplasms in addition to conventional basal cell carcinomas, typically appearing in the fourth to sixth decades of life. Although there are overlapping clinical manifestations, these findings help to differentiate the clinical syndrome associated with SUFU PVs from PTCH1 BCNS. Awareness of the clinicopathologic spectrum of SUFU-associated basaloid neoplasms is important for dermatologists and dermatopathologists because many (although not all) of these lesions are indolent and do not require aggressive surgical treatment. Importantly, because SUFU lies downstream of the protein smoothened, vismodegib and other smoothened inhibitors are unlikely to be effective therapies in this subset of patients.

Purpose: Sebaceous carcinoma is the third most common nonkeratinocyte skin cancer in the United States with 1,000 cases per year. The clinicopathologic features of sebaceous carcinoma and benign sebaceous neoplasms (adenomas, sebaceomas) can overlap, highlighting the need for molecular biomarkers to improve classification. This study describes the genomic and transcriptomic landscape of sebaceous neoplasms in order to understand tumor etiology and biomarkers relevant for diagnosis and treatment., Experimental Design: We performed whole-genome sequencing (WGS) and whole-transcriptome sequencing (WTS) of sebaceous neoplasms from six academic and two federal healthcare facilities in the United States diagnosed between January 1, 1999, and December 31, 2021., Results: We evaluated 98 sebaceous neoplasms: 64 tumors (32 adenomas, 2 sebaceomas, 5 atypical sebaceous neoplasms, 25 carcinomas) had sufficient material for WGS, 96 tumors (42 adenomas, 11 sebaceomas, 8 atypical sebaceous neoplasms, 35 carcinomas) had sufficient material for WTS, and 62 tumors (31 adenomas, 2 sebaceomas, 5 atypical sebaceous neoplasms, 24 carcinomas) had sufficient material for combined WGS and WTS. Overall, we found decreased cholesterol biosynthesis and increased TP53 mutations, copy number gains (chromosome 6, 8q, and/or 18), and tumor mutation burden-high (>10 mutations/MB) in carcinomas compared to adenomas. Although diminished compared to adenomas, most carcinomas still had higher cholesterol biosynthesis than nonmalignant skin. Multiomics profiling also supported a precancerous model of tumor evolution with sebaceomas and atypical sebaceous neoplasms being likely intermediate lesions., Conclusions: The study findings highlight key diagnostic biomarkers for sebaceous carcinoma and suggest that immunotherapy and modulation of cholesterol biosynthesis could be effective treatment strategies., (©2024 American Association for Cancer Research.)

The present study introduces new regression formulae that address several challenges of current subadult stature estimation methods by 1) using a large, contemporary, cross-sectional sample of subadult skeletal remains; 2) generating regression models using both lengths and breadths; 3) utilizing both linear and nonlinear regression models to accommodate the nonlinear shape of long bone growth; and 4) providing usable prediction intervals for estimating stature. Eighteen long bone measurements, stature, and age were collected from computed tomography images for a sample of individuals (n = 990) between birth and 20 years from the United States. The bivariate relationship between long bone measurements and stature was modeled using linear and nonlinear methods on an 80% training sample and evaluated on a 20% testing sample. Equations were generated using pooled-sex samples. Goodness of fit was evaluated using Kolmogorov-Smirnov tests and mean absolute deviation (MAD). Accuracy and precision were quantified using percent testing accuracy and Bland-Altman plots. In total, 38 stature estimation equations were created and evaluated, all achieving testing accuracies greater than 90%. Nonlinear models generated better fits compared to linear counterparts and generally produced smaller MAD (3.65 - 15.90cm). Length models generally performed better than breadth models, and a mixture of linear and nonlinear methods resulted in highest testing accuracies. Model performance was not biased by sex, age, or measurement type. A freely available, online graphical user interface is provided for immediate use of the models by practitioners in forensic anthropology and will be expanded to include bioarchaeological contexts in the future., (© 2024. The Author(s).)

Purpose: The purpose of this study was to develop recommendations for the diagnostic evaluation and surgical management of cutaneous melanoma (CM) and atypical Spitz tumors (AST) and non-Spitz melanocytic tumors (melanocytomas) in pediatric (age 0-10 years) and adolescent (age 11-18 years) patients., Methods: A Children's Oncology Group-led panel with external, multidisciplinary CM specialists convened to develop recommendations on the basis of available data and expertise., Results: Thirty-three experts from multiple specialties (cutaneous/medical/surgical oncology, dermatology, and dermatopathology) established recommendations with supporting data from 87 peer-reviewed publications., Recommendations: (1) Excisional biopsies with 1-3 mm margins should be performed when feasible for clinically suspicious melanocytic neoplasms. (2) Definitive surgical treatment for CM, including wide local excision and sentinel lymph node biopsy (SLNB), should follow National Comprehensive Cancer Network Guidelines in the absence of data from pediatric-specific surgery trials and/or cohort studies. (3) Accurate classification of ASTs as benign or malignant is more likely with immunohistochemistry and next-generation sequencing. (4) It may not be possible to classify some ASTs as likely/definitively benign or malignant after clinicopathologic and/or molecular correlation, and these Spitz tumors of uncertain malignant potential should be excised with 5 mm margins. (5) ASTs favored to be benign should be excised with 1- to 3-mm margins if transected on biopsy. (6) Re-excision is not necessary if the AST does not extend to the biopsy margin(s) when complete/excisional biopsy was performed. (7) SLNB should not be performed for Spitz tumors unless a diagnosis of CM is favored on clinicopathologic evaluation. (8) Non-Spitz melanocytomas have a presumed increased risk for progression to CM and should be excised with 1- to 3-mm margins if transected on biopsy. (9) Re-excision of non-Spitz melanocytomas is not necessary if the lesion is completely excised on biopsy.

Bone functional adaptation is routinely invoked to interpret skeletal morphology despite ongoing debate regarding the limits of the bone response to mechanical stimuli. The wide variation in human body mass presents an opportunity to explore the relationship between mechanical load and skeletal response in weight-bearing elements. Here, we examine variation in femoral macroscopic morphology as a function of body mass index (BMI), which is used as a metric of load history. A sample of 80 femora (40 female; 40 male) from recent modern humans was selected from the Texas State University Donated Skeletal Collection. Femora were imaged using x-ray computed tomography (voxel size ~0.5 mm), and segmented to produce surface models. Landmark-based geometric morphometric analyses based on the Coherent Point Drift algorithm were conducted to quantify shape. Principal components analyses were used to summarize shape variation, and component scores were regressed on BMI. Within the male sample, increased BMI was associated with a mediolaterally expanded femoral shaft, as well as increased neck-shaft angle and decreased femoral neck anteversion angle. No statistically significant relationships between shape and BMI were found in the female sample. While mechanical stimulus has traditionally been applied to changes in long bong diaphyseal shape it appears that bone functional adaptation may also result in fundamental changes in the shape of skeletal elements., (© 2024 American Association for Anatomy.)

Genetic engineering of allogeneic cell therapeutics that fully prevents rejection by a recipient's immune system would abolish the requirement for immunosuppressive drugs or encapsulation and support large-scale manufacturing of off-the-shelf cell products. Previously, we generated mouse and human hypoimmune pluripotent (HIP) stem cells by depleting HLA class I and II molecules and overexpressing CD47 (B2M -/- CIITA -/- CD47 + ). To determine whether this strategy is successful in non-human primates, we engineered rhesus macaque HIP cells and transplanted them intramuscularly into four allogeneic rhesus macaques. The HIP cells survived unrestricted for 16 weeks in fully immunocompetent allogeneic recipients and differentiated into several lineages, whereas allogeneic wild-type cells were vigorously rejected. We also differentiated human HIP cells into endocrinologically active pancreatic islet cells and showed that they survived in immunocompetent, allogeneic diabetic humanized mice for 4 weeks and ameliorated diabetes. HIP-edited primary rhesus macaque islets survived for 40 weeks in an allogeneic rhesus macaque recipient without immunosuppression, whereas unedited islets were quickly rejected., (© 2023. The Author(s).)

Dental enamel formation is coordinated by ameloblast differentiation, production of enamel matrix proteins, and crystal growth. The factors regulating ameloblast differentiation are not fully understood. Here we show that the high mobility group N (HMGN) nucleosomal binding proteins modulate the rate of ameloblast differentiation and enamel formation. We found that HMGN1 and HMGN2 proteins are downregulated during mouse ameloblast differentiation. Genetically altered mice lacking HMGN1 and HMGN2 proteins show faster ameloblast differentiation and a higher rate of enamel deposition in mice molars and incisors. In vitro differentiation of induced pluripotent stem cells to dental epithelium cells showed that HMGN proteins modulate the expression and chromatin accessibility of ameloblast-specific genes and affect the binding of transcription factors epiprofin and PITX2 to ameloblast-specific genes. Our results suggest that HMGN proteins regulate ameloblast differentiation and enamel mineralization by modulating lineage-specific chromatin accessibility and transcription factor binding to ameloblast regulatory sites., Competing Interests: Declaration of Conflicting InterestsThe authors declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Objectives: To investigate current practices and attitudes regarding use of adjuvant immunotherapy and prognostic gene expression profile (GEP) testing among melanoma medical and surgical oncologists., Methods: An anonymous RedCap-based survey was emailed to ~300 melanoma experts., Results: Respondents generally favored adjuvant immunotherapy over observation (73% for all Stage IIIA, 50% for Stage IIB/IIC) and cited a minimum 10-year recurrence risk of 11%-20% (48%) or 21%-30% (33%) to justify treatment, but acknowledged that risks of serious adverse events may outweigh potential benefits for some Stage IIB/IIC patients. While GEP test results did not strongly influence decision-making regarding follow-up or intervention, most were receptive to randomized trials using GEP testing to identify subsets of Stage IIB/IIC (74%) and Stage IB/IIA (54%) patients who may not or may, respectively, benefit from adjuvant therapy., Conclusion: Although most respondents do not routinely use GEP testing, many would participate in clinical trials to determine clinical utility., (© 2023 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.)

Background: Fibroblast growth factor receptor-3 (FGFR3) gain-of-function mutations are linked to achondroplasia. Infigratinib, a FGFR1-3 tyrosine kinase inhibitor, improves skeletal growth in an achondroplasia mouse model. FGFs and their receptors have critical roles in developing teeth, yet effects of infigratinib on tooth development have not been assessed. Dentoalveolar and craniofacial phenotype of Wistar rats dosed with low (0.1 mg/kg) and high (1.0 mg/kg) dose infigratinib were evaluated using micro-computed tomography, histology, and immunohistochemistry., Results: Mandibular third molars were reduced in size and exhibited aberrant crown and root morphology in 100% of female rats and 80% of male rats at high doses. FGFR3 and FGF18 immunolocalization and extracellular matrix protein expression were unaffected, but cathepsin K (CTSK) was altered by infigratinib. Cranial vault bones exhibited alterations in dimension, volume, and density that were more pronounced in females. In both sexes, interfrontal sutures were significantly more patent with high dose vs vehicle., Conclusions: High dose infigratinib administered to rats during early stages affects dental and craniofacial development. Changes in CTSK from infigratinib in female rats suggest FGFR roles in bone homeostasis. While dental and craniofacial disruptions are not expected at therapeutic doses, our findings confirm the importance of dental monitoring in clinical studies., (© 2023 American Association for Anatomy.)

Targeted cancer treatments-designed to interfere with specific molecular signals responsible for tumor survival and progression-have shown benefit over conventional chemotherapies but may lead to diverse cutaneous adverse effects. This review highlights clinically significant dermatologic toxicities and their associated histopathologic findings, resulting from various targeted cancer drugs. Case reports and series, clinical trials, reviews, and meta-analyses are included for analysis and summarized herein. Cutaneous side effects resulting from targeted cancer therapies were reported with incidences as high as 90% for certain medications, and reactions are often predictable based on mechanism(s) of action of a given drug. Common and important reaction patterns included: acneiform eruptions, neutrophilic dermatoses, hand-foot skin reaction, secondary cutaneous malignancies, and alopecia. Clinical and histopathologic recognition of these toxicities remains impactful for patient care., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Chronic kidney disease (CKD) is characterized by kidney damage and loss of renal function. CKD mineral and bone disorder (CKD-MBD) describes the dysregulation of mineral homeostasis, including hyperphosphatemia and elevated parathyroid hormone (PTH) secretion, skeletal abnormalities, and vascular calcification. CKD-MBD impacts the oral cavity, with effects including salivary gland dysfunction, enamel hypoplasia and damage, increased dentin formation, decreased pulp volume, pulp calcifications, and altered jaw bones, contributing to clinical manifestations of periodontal disease and tooth loss. Underlying mechanisms are not fully understood, and CKD mouse models commonly require invasive procedures with high rates of infection and mortality. We aimed to characterize the dentoalveolar effects of an adenine diet (AD)-induced CKD (AD-CKD) mouse model. Eight-week-old C57BL/6J mice were provided either a normal phosphorus diet control (CTR) or adenine and high-phosphorus diet CKD to induce kidney failure. Mice were euthanized at 15 weeks old, and mandibles were collected for micro-computed tomography and histology. CKD mice exhibited kidney failure, hyperphosphatemia, and hyperparathyroidism in association with porous cortical bone in femurs. CKD mice showed a 30% decrease in molar enamel volume compared to CTR mice. Enamel wear was associated with reduced ductal components, ectopic calcifications, and altered osteopontin (OPN) deposition in submandibular salivary glands of CKD mice. Molar cusps in CKD mice were flattened, exposing dentin. Molar dentin/cementum volume increased 7% in CKD mice and pulp volume decreased. Histology revealed excessive reactionary dentin and altered pulp-dentin extracellular matrix proteins, including increased OPN. Mandibular bone volume fraction decreased 12% and bone mineral density decreased 9% in CKD versus CTR mice. Alveolar bone in CKD mice exhibited increased tissue-nonspecific alkaline phosphatase localization, OPN deposition, and greater osteoclast numbers. AD-CKD recapitulated key aspects reported in CKD patients and revealed new insights into CKD-associated oral defects. This model has potential for studying mechanisms of dentoalveolar defects or therapeutic interventions. © 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR)., (© 2023 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).)

Importance: Therapy for advanced melanoma has transformed during the past decade, but early detection and prognostic assessment of cutaneous melanoma (CM) remain paramount goals. Best practices for screening and use of pigmented lesion evaluation tools and gene expression profile (GEP) testing in CM remain to be defined., Objective: To provide consensus recommendations on optimal screening practices and prebiopsy diagnostic, postbiopsy diagnostic, and prognostic assessment of CM., Evidence Review: Case scenarios were interrogated using a modified Delphi consensus method. Melanoma panelists (n = 60) were invited to vote on hypothetical scenarios via an emailed survey (n = 42), which was followed by a consensus conference (n = 51) that reviewed the literature and the rationale for survey answers. Panelists participated in a follow-up survey for final recommendations on the scenarios (n = 45)., Findings: The panelists reached consensus (≥70% agreement) in supporting a risk-stratified approach to melanoma screening in clinical settings and public screening events, screening personnel recommendations (self/partner, primary care provider, general dermatologist, and pigmented lesion expert), screening intervals, and acceptable appointment wait times. Participants also reached consensus that visual and dermoscopic examination are sufficient for evaluation and follow-up of melanocytic skin lesions deemed innocuous. The panelists reached consensus on interpreting reflectance confocal microscopy and some but not all results from epidermal tape stripping, but they did not reach consensus on use of certain pigmented lesion evaluation tools, such as electrical impedance spectroscopy. Regarding GEP scores, the panelists reached consensus that a low-risk prognostic GEP score should not outweigh concerning histologic features when selecting patients to undergo sentinel lymph node biopsy but did not reach consensus on imaging recommendations in the setting of a high-risk prognostic GEP score and low-risk histology and/or negative nodal status., Conclusions and Relevance: For this consensus statement, panelists reached consensus on aspects of a risk-stratified approach to melanoma screening and follow-up as well as use of visual examination and dermoscopy. These findings support a practical approach to diagnosing and evaluating CM. Panelists did not reach consensus on a clearly defined role for GEP testing in clinical decision-making, citing the need for additional studies to establish the clinical use of existing GEP assays.

Manufacturing autologous chimeric antigen receptor (CAR) T cell therapeutics is complex, and many patients experience treatment delays or cannot be treated at all. Although current allogeneic CAR products have the potential to overcome manufacturing bottlenecks, they are subject to immune rejection and failure to persist in the host, and thus do not provide the same level of efficacy as their autologous counterparts. Here, we aimed to develop universal allogeneic CAR T cells that evade the immune system and produce a durable response. We generated human hypoimmune (HIP) T cells with disrupted B2M, CIITA, and TRAC genes using CRISPR-Cas9 editing. In addition, CD47 and anti-CD19 CAR were expressed using lentiviral transduction. These allogeneic HIP CD19 CAR T cells were compared to allogeneic CD19 CAR T cells that only expressed the anti-CD19 CAR (allo CAR T). In vitro assays for cancer killing and exhaustion revealed no differences between allo CAR T and HIP CAR T cells, confirming that the HIP edits did not negatively affect T cell performance. Clearance of CD19 + tumors by HIP CAR T cells in immunodeficient NSG mice was comparable to that of allo CAR T cells. In fully immunocompetent humanized mice, HIP CAR T cells significantly outperformed allo CAR T cells, showed improved persistence and expansion, and provided lasting cancer clearance. Furthermore, CD47-targeting safety strategies reliably and specifically eliminated HIP CAR T cells. These findings suggest that universal allogeneic HIP CAR T cell-based therapeutics might overcome the limitations associated with poor persistence of allogeneic CAR T cells and exert durable anti-tumor responses., (© 2023. The Author(s).)

Background: Few prospective studies have evaluated local recurrence rates (LRR) after excision of desmoplastic melanoma (DM); however, several retrospective studies have reported high LRR., Objective: To determine LRR after excision of DM and evaluate factors affecting LRR., Materials and Methods: Systematic review of the PubMed, Embase, and Web of Science databases was performed to identify studies reporting local recurrence after excision of DM with conventional wide local excision (WLE), Mohs micrographic surgery (MMS), or staged excision (SE). Meta-analysis was performed to calculate summary LRR and pooled risk ratios (RR)., Results: Literature search identified 4 studies evaluating MMS or SE (total n = 61 DM). 53 studies assessed WLE ( n = 3,080) and were analyzed quantitatively. The overall LRR after WLE of DM was 21% (95% CI, 0.16-0.28; n = 2,308). Local recurrence rate was higher with positive/unknown histologic excision margins (49%, 95% CI, 0.25-0.74; n = 91) versus negative histologic margins (11%, 95% CI, 0.07-0.17; n = 1,075; [ p < .01]). Neurotropism was also associated with increased LRR (RR, 1.79; 95% CI, 1.34-2.38, p < .01; n = 644)., Conclusion: DM has high LRR after WLE. Local recurrence risk was greatest with positive excision margins, indicating the importance of achieving negative microscopic margins. Greater study of MMS and SE for DM is required., (Copyright © 2023 by the American Society for Dermatologic Surgery, Inc. Published by Wolters Kluwer Health, Inc. All rights reserved.)

Background: Given the results of the recent KEYNOTE-716 trial, the performance of sentinel lymph node (SLN) biopsy for patients with clinical stage IIB/C melanoma has been questioned., Objective: Determine the utility of SLN status in guiding the recommendations for adjuvant therapy., Methods: Patients with clinical stage IIB/C cutaneous melanoma who underwent wide local excision and SLN biopsy between 2004 and 2011 were identified from the Surveillance, Epidemiology, and End Results database. Two prognostic models, with and without SLN status, were developed predicting risk of melanoma-specific death (MSD). The primary outcome was net benefit at treatment thresholds of 20% to 40% risk of 5-year MSD., Results: For the 4391 patients included, the 5-year MSD rate was 46%. The model estimating 5-year MSD risk that included SLN status provided greater net benefit at treatment thresholds from 30% to 78% compared to the model without SLN status. The added net benefit for the SLN biopsy-containing model persisted in subgroup analysis of patients in different age groups and with various T stages., Limitations: Retrospective study., Conclusions: A prognostic model with SLN status estimating patient risk for 5-year MSD provides superior net benefit compared to a model with primary tumor staging factors alone for threshold mortality rates ≥30%., Competing Interests: Conflicts of interest Bartlett receives institutional research support from SkylineDx and discloses an honorarium from Excite International. Karakousis is a PI of an investigator-initiated trial with institutional support by Merck and serves on the Merck advisory board. The other authors have no conflict to disclose., (Copyright © 2022 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.)

Biological data are frequently nonlinear, heteroscedastic and conditionally dependent, and often researchers deal with missing data. To account for characteristics common in biological data in one algorithm, we developed the mixed cumulative probit (MCP), a novel latent trait model that is a formal generalization of the cumulative probit model usually used in transition analysis. Specifically, the MCP accommodates heteroscedasticity, mixtures of ordinal and continuous variables, missing values, conditional dependence and alternative specifications of the mean response and noise response. Cross-validation selects the best model parameters (mean response and the noise response for simple models, as well as conditional dependence for multivariate models), and the Kullback-Leibler divergence evaluates information gain during posterior inference to quantify mis-specified models (conditionally dependent versus conditionally independent). Two continuous and four ordinal skeletal and dental variables collected from 1296 individuals (aged birth to 22 years) from the Subadult Virtual Anthropology Database are used to introduce and demonstrate the algorithm. In addition to describing the features of the MCP, we provide material to help fit novel datasets using the MCP. The flexible, general formulation with model selection provides a process to robustly identify the modelling assumptions that are best suited for the data at hand., (© 2023 The Authors.)

Bone sialoprotein (BSP) is an extracellular matrix (ECM) protein associated with mineralized tissues, particularly bone and cementum. BSP includes functional domains implicated in collagen binding, hydroxyapatite nucleation, and cell signaling, although its function(s) in osteoblast and osteoclast differentiation and function remain incompletely understood. Genetic ablation of BSP in Ibsp knockout ( Ibsp -/- ) mice results in developmental bone mineralization and remodeling defects, with alveolar bone more severely affected than the femurs and tibias of the postcranial skeleton. The role of BSP in alveolar bone healing has not been studied. We hypothesized that BSP ablation would cause defective alveolar bone healing. We employed a maxillary first molar extraction socket healing model in 42-d postnatal Ibsp -/- and wild-type (WT) control mice. Tissues were collected at 0, 7, 14, 21, and 56 d postprocedure (dpp) for analysis by micro-computed tomography (microCT), histology, in situ hybridization (ISH), immunohistochemistry (IHC), and quantitative polymerase chain reaction (qPCR) array. As expected, alveolar bone healing progressed in WT mice with increasing bone volume fraction (BV/TV), bone mineral density (BMD), and tissue mineral density (TMD), transitioning from woven to mature bone from 7 to 56 dpp. Ibsp messenger RNA (mRNA) and BSP protein were strongly expressed during alveolar bone healing in parallel with other osteogenic markers. Compared to WT, Ibsp -/- mice exhibited 50% to 70% reduced BV/TV and BMD at all time points, 7% reduced TMD at 21 dpp, abnormally increased Col1a1 and Alpl mRNA expression, and persistent presence of woven bone and increased bone marrow in healing sockets. qPCR revealed substantially dysregulated gene expression in alveolar bone of Ibsp -/- versus WT mice, with significantly disrupted expression of 45% of tested genes in functional groups, including markers for osteoblasts, osteoclasts, mineralization, ECM, cell signaling, and inflammation. We conclude that BSP is a critical and nonredundant factor for alveolar bone healing, and its absence disrupts multiple major pathways involved in appropriate healing.

Background: Spitzoid morphology in familial melanoma has been associated with germline variants in POT1 , a telomere maintenance gene (TMG), suggesting a link between telomere biology and spitzoid differentiation., Objective: To assess if familial melanoma cases associated with germline variants in TMG ( POT1 , ACD , TERF2IP , and TERT ) commonly exhibit spitzoid morphology., Methods: In this case series, melanomas were classified as having spitzoid morphology if at least 3 of 4 dermatopathologists reported this finding in ≥25% of tumor cells. Logistic regression was used to calculate odds ratios (OR) of spitzoid morphology compared to familial melanomas from unmatched noncarriers that were previously reviewed by a National Cancer Institute dermatopathologist., Results: Spitzoid morphology was observed in 77% (23 of 30), 75% (3 of 4), 50% (2 of 4), and 50% (1 of 2) of melanomas from individuals with germline variants in POT1 , TERF2IP , ACD , and TERT , respectively. Compared to noncarriers ( n  = 139 melanomas), POT1 carriers (OR = 225.1, 95% confidence interval: 51.7-980.5; P  < .001) and individuals with TERF2IP, ACD, and TERT variants (OR = 82.4, 95% confidence interval: 21.3-494.6; P  < .001) had increased odds of spitzoid morphology., Limitations: Findings may not be generalizable to nonfamilial melanoma cases., Conclusion: Spitzoid morphology in familial melanoma could suggest germline alteration of TMG., Competing Interests: None disclosed.

Background: Since their first approval 25 years ago, monoclonal antibodies (mAbs) have become important targeted cancer therapeutics. However, dermatologic toxicities associated with non-immune checkpoint inhibitor (non-ICI) mAbs may complicate the course of cancer treatment. Data on the incidence and types of these reactions are limited., Methods: A comprehensive review was conducted on dermatologic toxicities associated with different classes of non-ICI mAbs approved for treatment of solid tumors and hematologic malignancies. The review included prospective Phase 1, 2, and 3 clinical trials; retrospective literature reviews; systematic reviews/meta-analyses; and case series/reports., Results: Dermatologic toxicities were associated with several types of non-ICI mAbs. Inflammatory reactions were the most common dermatologic toxicities, manifesting as maculopapular, urticarial, papulopustular/acneiform, and lichenoid/interface cutaneous adverse events (cAEs) with non-ICI mAbs. Immunobullous reactions were rare and a subset of non-ICI mAbs were associated with the development of vitiligo cAEs., Conclusion: Dermatologic toxicities of non-ICI mAbs are diverse and mostly limited to inflammatory reactions. Awareness of the spectrum of the histopathologic patterns of cAE from non-ICI mAbs therapy is critical in the era of oncodermatology and oncodermatopathology., (© 2022 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Competing Interests: Conflicts of interest None disclosed.

Background and Objectives: Type II diabetes mellitus (T2DM) can lead to an immunosuppressed state, but whether T2DM is associated with worse outcomes for patients with melanoma has not been well studied., Methods: Consecutive patients diagnosed with clinical stage I-II cutaneous melanoma who underwent sentinel lymph node biopsy at a single institution (2007-2016) were identified. Melanoma characteristics and recurrence/survival outcomes were compared between patients with and without T2DM at the time of melanoma diagnosis., Results: Of 1128 patients evaluated, 111 (9.8%) had T2DM (n = 94 [84.7%] non-insulin dependent [NID-T2DM]; n = 17 [15.3%] insulin dependent [ID-T2DM]). T2DM patients were more likely to be older (odds ratio [OR] 1.04, p < 0.001), male (OR 2.15, p = 0.003), have tumors >1.0 mm (OR 1.88, p = 0.023), and have microsatellitosis (OR 2.29, p = 0.030). Five-year cumulative incidence of melanoma recurrence was significantly higher for patients with ID-T2DM (46.7% ID-T2DM vs. 25.7% NID-T2DM vs. 17.1% no T2DM, p < 0.001), and on multivariable analysis, ID-T2DM was independently associated with melanoma recurrence (hazard ratio 2.57, p = 0.015). No difference in 5-year disease-specific survival was observed between groups., Conclusions: ID-T2DM appears to be associated with more advanced melanoma and increased risk for melanoma recurrence. Further study as to whether this reflects differences in tumor biology or host factors is warranted., (© 2022 Wiley Periodicals LLC.)

Citrate is a critical metabolic substrate and key regulator of energy metabolism in mammalian cells. It has been known for decades that the skeleton contains most (>85%) of the body's citrate, but the question of why and how this metabolite should be partitioned in bone has received singularly little attention. Here, we show that osteoblasts use a specialized metabolic pathway to regulate uptake, endogenous production, and the deposition of citrate into bone. Osteoblasts express high levels of the membranous Na + -dependent citrate transporter solute carrier family 13 member 5 ( Slc13a5 ) gene. Inhibition or genetic disruption of Slc13a5 reduced osteogenic citrate uptake and disrupted mineral nodule formation. Bones from mice lacking Slc13a5 globally, or selectively in osteoblasts, showed equivalent reductions in cortical thickness, with similarly compromised mechanical strength. Surprisingly, citrate content in mineral from Slc13a5 -/- osteoblasts was increased fourfold relative to controls, suggesting the engagement of compensatory mechanisms to augment endogenous citrate production. Indeed, through the coordinated functioning of the apical membrane citrate transporter SLC13A5 and a mitochondrial zinc transporter protein (ZIP1; encoded by Slc39a1 ), a mediator of citrate efflux from the tricarboxylic acid cycle, SLC13A5 mediates citrate entry from blood and its activity exerts homeostatic control of cytoplasmic citrate. Intriguingly, Slc13a5 -deficient mice also exhibited defective tooth enamel and dentin formation, a clinical feature, which we show is recapitulated in primary teeth from children with SLC13A5 mutations. Together, our results reveal the components of an osteoblast metabolic pathway, which affects bone strength by regulating citrate deposition into mineral hydroxyapatite.

Competing Interests: Conflicts of interest None disclosed.

Background: Programmed cell death protein (PD-1) and programmed death-ligand 1 (PD-L1) inhibition checkpoint blockade leads to various cutaneous adverse reactions, including bullous pemphigoid and lichen-planus-like reactions. However, lichen planus pemphigoides (LPP), manifesting histopathologic features of both lichen planus and bullous pemphigoid, has more rarely been associated with immunotherapy., Methods: The clinical and histopathologic findings of three patients were examined, and a review of cases of LPP and bullous lichen planus secondary to PD-1 inhibitor therapy was performed., Results: Three patients (two with advanced non-small-cell lung adenocarcinoma and the third with metastatic breast cancer) presented with both lichenoid eruptions and bullae. Biopsy of the lesions revealed lichenoid tissue reactions in all three patients. Together with the histopathologic findings, direct immunofluorescence (DIF) showing linear C3 and IgG deposition and positive enzyme-linked immunosorbent assay (ELISA) showing BP180 positivity supported a diagnosis of LPP in two patients. The third patient in our series also showed confirmatory ELISA testing supporting LPP., Conclusions: Lichen planus pemphigoides is a distinct cutaneous toxicity to checkpoint inhibitor therapy illustrates a possible pathogenic mechanism and the importance of dermatopathology recognition to render an accurate diagnosis., (© 2022 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Background: Approval of adjuvant anti-programmed cell death protein 1 therapy for pathologic stage IIB/C cutaneous melanoma has led some to question the role of sentinel lymph node (SLN) biopsy in the clinical stage IIB/C disease., Objective: To determine the prognostic significance of SLN staging on disease-specific survival (DSS) for clinical stage IIB/C primary cutaneous melanoma in the preimmunotherapy era., Methods: A retrospective cohort study was performed evaluating patients who underwent excision of clinical stage IIB/C cutaneous melanoma using the Surveillance, Epidemiology, and End Results database (2004-2011). Patients who did and did not undergo SLN biopsy were compared using propensity matching, and among those who underwent SLN biopsy, matched patients were further stratified by SLN status (SLN positive [SLN+] or SLN negative [SLN-])., Results: Of the 8562 patients evaluated, 6021 (70.3%) underwent SLN biopsy. SLN positivity was associated with significantly reduced 5-year DSS among matched patients who underwent SLN biopsy (47.1% SLN+ vs 75.5% SLN-; P < .001). Five-year DSS remained significantly different across matched T-stages: T3b (54.2% SLN+ vs 64.8% SLN-; P = .004), T4a (55.5% SLN+ vs 71.6% SLN-; P = .001), and T4b (38.6% SLN+ vs 60.9% SLN-; P < .001)., Limitations: Retrospective study., Conclusion: For patients with clinical stage IIB/C cutaneous melanoma, SLN status provides essential prognostic information., Competing Interests: Conflicts of interest None disclosed., (Copyright © 2022 American Academy of Dermatology, Inc. Published by Elsevier Inc. All rights reserved.)

The periodontium supports and attaches teeth via mineralized and nonmineralized tissues. It consists of two, unique mineralized tissues, cementum and alveolar bone. In between these tissues, lies an unmineralized, fibrous periodontal ligament (PDL), which distributes occlusal forces, nourishes and invests teeth, and harbors progenitor cells for dentoalveolar repair. Many unanswered questions remain regarding periodontal biology. This review will focus on recent research providing insights into one enduring mystery: the precise regulation of the hard-soft tissue borders in the periodontium which define the interfaces of the cementum-PDL-alveolar bone structure. We will focus on advances in understanding the molecular mechanisms that maintain the unmineralized PDL "between a rock and a hard place" by regulating the mineralization of cementum and alveolar bone., (© 2022 The Authors. genesis published by Wiley Periodicals LLC.)

Biallelic ectonucleotide pyrophosphatase/phosphodiesterase 1 (ENPP1) deficiency induces vascular/soft tissue calcifications in generalized arterial calcification of infancy (GACI), and low bone mass with phosphate-wasting rickets in GACI survivors (autosomal hypophosphatemic rickets type-2). ENPP1 haploinsufficiency induces early-onset osteoporosis and mild phosphate wasting in adults. Both conditions demonstrate the unusual combination of reduced accrual of skeletal mineral, yet excess and progressive heterotopic mineralization. ENPP1 is the only enzyme that generates extracellular pyrophosphate (PPi), a potent inhibitor of both bone and heterotopic mineralization. Life-threatening vascular calcification in ENPP1 deficiency is due to decreased plasma PPi; however, the mechanism by which osteopenia results is not apparent from an understanding of the enzyme's catalytic activity. To probe for catalysis-independent ENPP1 pathways regulating bone, we developed a murine model uncoupling ENPP1 protein signaling from ENPP1 catalysis, Enpp1 T238A mice. In contrast to Enpp1 asj mice, which lack ENPP1, Enpp1 T238A mice have normal trabecular bone microarchitecture and favorable biomechanical properties. However, both models demonstrate low plasma Pi and PPi, increased fibroblast growth factor 23 (FGF23), and by 23 weeks, osteomalacia demonstrating equivalent phosphate wasting in both models. Reflecting findings in whole bone, calvarial cell cultures from Enpp1 asj mice demonstrated markedly decreased calcification, elevated transcription of Sfrp1, and decreased nuclear β-catenin signaling compared to wild-type (WT) and Enpp1 T238A cultures. Finally, the decreased calcification and nuclear β-catenin signaling observed in Enpp1 asj cultures was restored to WT levels by knockout of Sfrp1. Collectively, our findings demonstrate that catalysis-independent ENPP1 signaling pathways regulate bone mass via the expression of soluble Wnt inhibitors such as secreted frizzled-related protein 1 (SFRP1), whereas catalysis dependent pathways regulate phosphate homeostasis through the regulation of plasma FGF23. © 2022 American Society for Bone and Mineral Research (ASBMR)., (© 2022 American Society for Bone and Mineral Research (ASBMR).)

Background: The prognostic impact of tumor-infiltrating lymphocytes (TILs) on outcomes and treatment efficacy for patients with melanoma in the contemporary era remains poorly characterized., Methods: Consecutive patients who underwent wide excision and sentinel lymph node biopsy for cutaneous melanoma 1 mm thick or thicker at a single institution were identified (2006-2019). The patients were stratified based on primary tumor TIL status as brisk (bTILs), non-brisk (nbTILs), or absent (aTILs). Associations between patient factors and outcomes were analyzed using multivariable analysis., Results: Of the 1017 patients evaluated, 846 (83.2 %) had primary TILs [nbTILs (n = 759, 89.7 %) and bTILs (n = 87, 10.3 %)]. In the multivariable analysis, the patients with any type of TILs had higher rates of regression [odds ratio (OR), 1.86; p = 0.016], lower rates of acral lentiginous histology (OR, 0.22; p < 0.001), and lower rates of SLN positivity (OR, 0.64; p = 0.042) than those without TILs. The multivariable analysis found no association between disease-specific survival and bTILs [hazard ratio (HR), 1.04; p = 0.927] or nbTILs (HR, 0.89; p = 0.683). An association was found between bTILs and recurrence-free survival (RFS) advantage [bTILs (HR 0.46; p = 0.047), nbTILs (HR 0.71; p = 0.088)], with 5-year RFS rates of 84 % for bTILs, 71.8 % for nbTILs, and 68.4 % for aTILs (p = 0.044). For the 114 immune checkpoint blockade (ICB)-naïve patients who experienced a recurrence treated with ICB therapy, no association was observed between progression-free survival and bTILs (HR, 0.64; p = 0.482) or nbTILs (HR, 0.58; p = 0.176)., Conclusions: The prognostic significance of primary TILs in the contemporary melanoma era appears complex. Further studies characterizing the phenotype of TILs and their association with regional metastasis and responsiveness to ICB therapy are warranted., (© 2022. Society of Surgical Oncology.)

Competing Interests: Conflicts of interest None disclosed.

Competing Interests: Conflicts of interest None disclosed.

Observer error and agreement rates for craniometrics, odontometrics, and cranial and dental morphological traits have been inconsistently evaluated on three-dimensional cranial reconstructions and almost never assessed on subadult individuals. This study uses a computed tomography (CT) scan sample of 12 subadults aged between birth and 20 years from the Subadult Virtual Anthropology Database (SVAD) to evaluate intra- and inter-observer error and agreement rates associated to these four types of data on virtual crania. Forty-eight cranial landmarks, 33 standard inter-landmark distances (ILDs), 13 cranial macromorphoscopic traits, four permanent and four deciduous dental landmarks and measurements per tooth, and 21 permanent and 12 deciduous dental morphological traits were collected on each individual. Results matched or improved on published standards for dry bones, teeth, or dental casts. Technical Error of Measurement (TEM) associated with metric data ranged from 0.00 mm to 0.99 mm and relative TEM ranged from 0% to 5.76%. Cohen's kappa coefficient values for agreement on morphological traits scores were above K = 0.5 for 90% of the traits. Type III cranial landmarks showed higher error rates than Type I and II cranial landmarks. Agreement on dental morphology scores seemed influenced by observer experience and rater agreement improved when using di- or tri-chotomized grades. Skeletal maturity did not significantly affect error rates, meaning most craniofacial and dental metrics and morphological traits can be reliably obtained from virtual subadult crania., Competing Interests: Conflict of interest The authors declare no conflict of interest., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Competing Interests: The authors declare no conflicts of interest.

Competing Interests: The authors declare no conflicts of interest.

Background: Advances in molecular biology and genetics have contributed to breakthrough treatments directed at specific pathways associated with the development of cancer. Small-molecule inhibitors (Nibs) aimed at a variety of cellular pathways have been efficacious; however, they are associated with significant dermatologic toxicities., Methods: We conducted a comprehensive review of dermatologic toxicities associated with Nibs categorized into the following five groups: (a) mitogen-activated protein kinase; (b) growth factor/multi-tyrosine kinase; (c) cell division/DNA repair; (d) signaling associated with myeloproliferative neoplasms; and (e) other signaling pathways. Prospective phase I, II, or III clinical trials, retrospective literature reviews, systematic reviews/meta-analyses, and case reviews/reports were included for analysis., Results: Dermatologic toxicities reviewed were associated with every class of Nibs and ranged from mild to severe or life-threatening adverse skin reactions. Inflammatory reactions manifesting as maculopapular, papulopustular/acneiform, and eczematous lesions were frequent types of dermatologic toxicities seen with Nibs. Squamous cell carcinoma with keratoacanthoma-like features was associated with a subset of Nibs. Substantial overlap in dermatologic toxicities was found between Nibs., Conclusions: Dermatologic toxicities from Nibs are diverse and may overlap between classes of Nibs. Recognition of the various types of toxicities from Nibs is critical for patient care in the era of "oncodermatology/dermatopathology.", (© 2021 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Abstract: Dual immunohistochemical (IHC) staining with D2-40 and S100 improves detection of lymphatic invasion (LI) in primary cutaneous melanoma. However, limited data exist evaluating this technique using other melanocytic markers, and thus, the optimal marker for detection of LI is unestablished. To address this knowledge gap, a case-control study was performed comparing melanoma specimens from 22 patients with known lymphatic spread (LS) with a control group of 11 patients without LS. Specimens underwent dual IHC staining with D2-40 and MART-1, SOX-10, and S100 to evaluate for LI. Receiver operating characteristic analysis was used to estimate each stain's accuracy for detection of LI. The LS group was more likely to be ≥65 years (P = 0.04), have a tumor thickness of ≥1 mm (P < 0.01), and have ulcerated tumors (P = 0.02). Detection of LI with D2-40/MART-1 significantly correlated with LS (P = 0.03), and the D2-40/MART-1 stain was most accurate for LI based on receiver operating characteristic curve analysis (area under the curve [AUC] 0.705) in comparison with D2-40/SOX-10 (AUC 0.575) and D2-40/S100 (AUC 0.633). These findings suggest that MART-1 may be the optimal melanocytic marker to combine with D2-40 for detection of LI in melanoma. Further studies are needed to determine the utility of routinely performing these stains for histopathologic analysis of melanoma., Competing Interests: The authors declare no conflicts of interest., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Cementum is a mineralized tissue that covers tooth roots and functions in the periodontal attachment complex. Cementocytes, resident cells of cellular cementum, share many characteristics with osteocytes, are mechanoresponsive cells that direct bone remodeling based on changes in loading. We hypothesized that cementocytes play a key role during orthodontic tooth movement (OTM). To test this hypothesis, we used 8-week-old male Wistar rats in a model of OTM for 2, 7, or 14 days (0.5 N), whereas unloaded contralateral teeth served as controls. Tissue and cell responses were analyzed by high-resolution micro-computed tomography, histology, tartrate-resistant acid phosphatase staining for odontoclasts/osteoclasts, and transmission electron microscopy. In addition, laser capture microdissection was used to collect cellular cementum, and extracted proteins were identified by liquid chromatography coupled to tandem mass spectrometry. The OTM model successfully moved first molars mesially more than 250 μm by 14 days introducing apoptosis in a small number of cementocytes and areas of root resorption on mesial and distal aspects. Cementocytes showed increased nuclear size and proportion of euchromatin suggesting cellular activity. Proteomic analysis identified 168 proteins in cellular cementum with 21 proteins found only in OTM sites and 54 proteins only present in control samples. OTM-down-regulated several extracellular matrix proteins, including decorin, biglycan, asporin, and periostin, localized to cementum and PDL by immunostaining. Furthermore, type IV collagen (COL14A1) was the protein most down-regulated (-45-fold) by OTM and immunolocalized to cells at the cementum-dentin junction. Eleven keratins were significantly increased by OTM, and a pan-keratin antibody indicated keratin localization primarily in epithelial remnants of Hertwig's epithelial root sheath. These experiments provide new insights into biological responses of cementocytes and cellular cementum to OTM., (Copyright © 2021 Elsevier Inc. All rights reserved.)

Background: Cellular cementum, a mineralized tissue covering apical tooth roots, grows by apposition to maintain the tooth in its occlusal position. We hypothesized that resident cementocytes would show morphological changes in response to cementum apposition, possibly implicating a role in cementum biology., Methods: Mandibular first molars were induced to super-erupt (EIA) by extraction of maxillary molars, promoting rapid new cementum formation. Tissue and cell responses were analyzed at 6 and/or 21 days post-procedure (dpp)., Results: High-resolution micro-computed tomography (micro-CT) and confocal laser scanning microscopy showed increased cellular cementum by 21 dpp. Transmission electron microscopy (TEM) revealed that cementocytes under EIA were 50% larger than control cells, supported by larger pore sizes detected by micro-CT. Cementocytes under EIA displayed ultrastructural changes consistent with increased activity, including increased cytoplasm and nuclear size. We applied EIA to Hyp mutant mice, where cementocytes have perilacunar hypomineralization defects, to test cell and tissue responses in an altered mechanoresponsive milieu. Hyp and WT molars displayed similar super-eruption, with Hyp molars exhibiting 28% increased cellular cementum area versus 22% in WT mice at 21 dpp. Compared to control, Hyp cementocytes featured well-defined, disperse euchromatin and a thick layer of peripherally condensed heterochromatin in nuclei, indicating cellular activity. Immunohistochemistry (IHC) for cementum markers revealed intense dentin matrix protein-1 expression and abnormal osteopontin deposition in Hyp mice. Both WT and Hyp cementocytes expressed gap junction protein, connexin 43., Conclusion: This study provides new insights into the EIA model and cementocyte activity in association with new cementum formation., (© 2021 American Academy of Periodontology.)