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Background: Black children have lower incidence yet worse survival than White and Latinx children with B‐cell acute lymphoblastic leukemia (B‐ALL). It is unclear how reported race/ethnicity (RRE) is associated with death in B‐ALL after accounting for differentially expressed genes associated with genetic ancestry. Methods: Using Phase 1 and 2 NCI TARGET B‐ALL cases (N = 273; RRE‐Black = 21, RRE‐White = 162, RRE‐Latinx = 69, RRE‐Other = 9, RRE‐Unknown = 12), we estimated proportions of African (AFR), European (EUR), and Amerindian (AMR) genetic ancestry. We estimated hazard ratios (HR) and 95% confidence intervals (95% CI) between ancestry and death while adjusting for RRE and clinical measures. We identified genes associated with genetic ancestry and adjusted for them in RRE and death associations. Results: Genetic ancestry varied within RRE (RRE‐Black, AFR proportion: Mean: 78.5%, Range: 38.2%–93.6%; RRE‐White, EUR proportion: Mean: 94%, Range: 1.6%–99.9%; RRE‐Latinx, AMR proportion: Mean: 52.0%, Range: 1.2%–98.7%). We identified 10, 1, and 6 differentially expressed genes (padjusted <0.05) associated with AFR, AMR, and EUR ancestry proportion, respectively. We found AMR and AFR ancestry were statistically significantly associated with death (AMR each 10% HR: 1.05, 95% CI: 1.03–1.17, AFR each 10% increase HR: 1.03, 95% CI:1.01–1.19). RRE differences in the risk of death were larger in magnitude upon adjustment for genes associated with genetic ancestry for RRE‐Black, but not RRE‐Latinx children (RRE‐Black HR: 3.35, 95% CI: 1.31, 8.53; RRE‐Latinx HR: 1.47, 0.88–2.45). Conclusions: Our work highlights B‐ALL survival differences by RRE after adjusting for ancestry differentially expressed genes suggesting other factors impacting survival are important. [ABSTRACT FROM AUTHOR]

Species delimitation has long been a difficult and controversial process, and different operational criteria often lead to different results. In particular, investigators using phenotypic vs. molecular data to delineate species may recognize different boundaries, especially if morphologically or ecologically differentiated populations have only recently diverged. Here we examine the genetic relationship between the widespread sunflower species Helianthus petiolaris and its narrowly distributed sand dune endemic sister species H. neglectus using sequence data from nine nuclear loci. The two species were initially described as distinct based on a number of minor morphological differences, somewhat different ecological tolerances, and at least one chromosomal rearrangement distinguishing them; but detailed molecular data has not been available until now. We find that, consistent with previous work, H. petiolaris is exceptionally genetically diverse. Surprisingly, H. neglectus harbors very similar levels of genetic diversity (average diversity across loci is actually slightly higher in H. neglectus). It is extremely unlikely that such a geographically restricted species could maintain these levels of genetic variation in isolation. In addition, the two species show very little evidence of any genetic divergence, and estimates of interspecific gene flow are comparable to gene flow estimates among regions within H. petiolaris. These results indicate that H. petiolaris and H. neglectus likely do not represent two distinct, isolated gene pools; H. neglectus is probably more accurately thought of as a geographically restricted, morphologically and ecologically distinct subspecies of H. petiolaris rather than a separate species. [ABSTRACT FROM AUTHOR]