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This i3 is a data visualization based on the Cell Stem Cell tenth anniversary theme of lineage tracing. Using Scopus citations of Cell Stem Cell research papers, it illustrates both the evolution of the stem cell field and the way new research builds on work that came before. Users can navigate the graphic and the represented papers by stem cell type, organism, and author online at cell.com/i3/cell-stem-cell/lineage. To view this SnapShot, open or download the PDF.

Augenlicht and colleagues raise concerns about the impact of diet on stem cell regulation and call for more careful reporting on dietary conditions used in mouse studies on this topic. We agree that specific conditions for animal housing and care should be reported, and we encourage this in our STAR Methods guidelines for all papers. However, moving forward we will require more detailed reporting on dietary information for mouse studies where the main scientific focus concerns stem cell functions, and especially metabolism. This will include vendor information, stock number, and feeding schedules within the STAR Methods section and Experimental Models section of the Key Resource Table. We hope this will provide further reproducibility, robustness, and clarity in the papers we publish.

Think back to where you were and what you were doing 10 years ago. Maybe you were in graduate school, maybe even high school, or perhaps you had just started your first lab and were working out how to transition from being a postdoc to being a leader of a scientific team. It’s likely that a lot has changed for you in the intervening time. For us at Cell Stem Cell the same is also true. Ten years ago during May (the time of writing both this editorial and the very first one), we were working frantically to finalize the content for our launch issue. For editors, especially, but also for the entire team, launching a new journal is an exciting but very stressful experience. We are a little frantic again this year, too, putting together all of the materials and plans for this tenth anniversary issue, but this time against the backdrop of a wealth of material to look back on and digest.When we started talking within the editorial team about a theme to use for our tenth anniversary, we focused on thinking how we could best showcase the great science we’ve had the pleasure to publish, and the ways in which all of these important contributions have helped to build and advance the field. Working from an idea that came from a colleague (credit where credit’s due!), we were inspired by the concept of “Lineage Tracing,” based on both the obvious connection to the stem cell field and the way new scientific discoveries build on those that came before. We took this theme and ran with it, and we have put together a variety of articles from a range of different contributors that we hope will showcase how the work that we’ve published has fit into and helped advance the field overall.We have four overall article types in our special journal feature, each of which highlights the “lineage” associated with some of our most widely appreciated papers in a distinct way. We based our selection of papers on a combination of citation information, download data, and, particularly for the more recent examples, collaboration with PLUM Analytics to look at readership and sharing. We then organized the papers into topical themes that we felt represent some of the key overall interest areas that have developed over the past 10 years, and we selected an approach for highlighting how the Cell Stem Cell studies fit in. For a series of Voices articles, we chose three papers from each of five topical areas—cancer stem cells, disease modeling, aging, epigenetics, and single-cell technology—and asked a scientist who cited each paper to write about how the work contributed to the development of their thinking. For three topics—organoid technology, reprogramming, and genome editing—we asked one author each from three of our most prominent papers to contribute to a Q&A discussing the current questions and future directions in these rapidly moving areas. Because we understand that many stem cell researchers are motivated by the potential for their work to ultimately help patients, we have also included a Profile that illustrates this type of trajectory by focusing on two Cell Stem Cell papers that formed the underlying basis of biotech startup journeys leading to clinical trials using modified RNA technology and cell transplantation. Lastly, to go behind the scenes for one of our most exciting recent papers and show just how much dedication and coordination went into it on all sides, we asked Hongjun Song, Guo-Li Ming, and Hengli Teng to put together a Backstory article about the work that led up to their 2016 paper on Zika infection of neural progenitors. This paper formed one of the major underpinnings of the subsequent CDC declaration about the link between Zika and microcephaly. We have two different forms of this Backstory article, one in the standard journal format that is relatively conventional, and then an enhanced, more immersive version online with additional images and embedded videos. This approach is a new experiment for us, so we’d love to hear from you if you enjoy it and would like to see more. You can pick up a print copy of this special issue at our booth, #719, at the ISSCR 2017 Annual Meeting, along with a copy of our latest “Best Of” edition in your delegate bag. There will also be a digital edition of the entire issue on our dedicated anniversary website, which will go live before the ISSCR meeting.Returning to online presentation, we would also like to highlight the interactive data visualization, or i3, that will form the cornerstone of our anniversary website, our cover image, and the theme for our “Pin to Win” badges at ISSCR 2017. The i3 is also part of the lineage tracing theme, and the underlying inspiration for the approach that we took in fact comes from representations of clonal analysis of hematopoiesis. The data being represented are Scopus citations of Cell Stem Cell papers year by year since launch. We chose to focus on research papers, and we then categorized them by stem cell type and organism. Using those parameters, you will be able to navigate around our online tool to look at the citation contribution of specific areas and stem cell types over time as the journal and field has developed, and even at specific authors or papers. Cell Stem Cell is of course just one journal of the many that publish stem cell papers, and citations are also only one measure of field size and interest. However, we often hear feedback that Cell Stem Cell is a “must read” journal for the stem cell community and that it mirrors the way the field is changing and evolving. So, we’d like to think that in addition to chronicling the evolution of Cell Stem Cell itself, this visualization also gives a window into the ways that the stem cell field has developed over time. We’re already seeing some surprising things from navigating around the tool as we set it up and we hope that you will be able to help us figure them out!Many, many people deserve thanks for their contributions to the success of Cell Stem Cell and the role the journal plays in the stem cell community. Within Cell Press we’ve had a wonderful team of scientific editors, assistants, production editors, marketing managers, and designers. Beyond that we of course owe a tremendous debt of gratitude to all of the authors who chose to send their work to us or to write review articles, and to the reviewers who gave us invaluable feedback that helped us both select which articles we choose to publish and improve the quality of the ones that do appear. Our advisory editorial board members have been a fantastic source of support and input as well, and they have helped us shape the journal and its contribution to the field. We have also very much appreciated our ongoing partnership with the ISSCR and their support of Cell Stem Cell as an affiliated journal. More proximally, we’d like to thank Thermo Fisher for their support of our anniversary website and overall feature.The stem cell field has changed a lot in the past decade, and although 10 years ago the reprogramming field was already starting to take off, many other areas that are important now, such as organoid technology, CRISPR/Cas9 genome editing, and single-cell sequencing analytics, weren’t on the radar or even in existence. If history is anything to go by, we can expect many more new developments and exciting changes in the future as stem cell research continues to grow and evolve. Here at Cell Stem Cell we all very much look forward to seeing what the next 10 years will bring.

If you have looked at the cover of this issue, you may be wondering why we chose a picture of an engineer repairing telephone wires. The link to stem cells might not be immediately apparent. However, if you look closely, you will see that there is an underlying theme. The telephone wires represent communication, and the drawing incorporates various elements of the interconnected network of ethical and practical considerations involved in regenerative medicine, some of which are highlighted in our issue (see if you can guess the artist whose work we are subtly emulating!). The engineer has a role to play too—as a depiction of the stem cell-based approaches that are tapping into that network to help make progress toward repair and regeneration.The underlying prompt for the cover theme came from this month's review section, which looks at the importance of communication at different stages of the research enterprise. In their Forum, Erica Haimes and Ken Taylor advocate for strong connections between researchers, clinicians, and patients to help ensure smooth and effective provision of materials for scientific research. Once materials are available, discussion and exchange of reagents is more straightforward if information about them is presented clearly. To that end, the two Letters both comment and build upon a Forum that appeared in our April issue calling for a standardized approach to nomenclature for human pluripotent stem cell lines (Luong et al., 2011xLuong, M.X., Auerbach, J., Crook, J.M., Daheron, L., Hei, D., Lomax, G., Loring, J.F., Ludwig, T., Schlaeger, T.M., Smith, K.P. et al. Cell Stem Cell. 2011; 8: 357–359Abstract | Full Text | Full Text PDF | PubMed | Scopus (15)See all ReferencesLuong et al., 2011). The Perspective from Christopher Goldring and colleagues arose from communication, as it is based on discussions between authors from a broad range of academic institutions and companies at a workshop. This article outlines the many different factors that need to be taken into account for assessing the safety of any stem cell-based therapy, regardless of the cell type and source being used. Richard Maziarz and Dawn Driscoll look at the other end of the process by outlining the need for early interaction between those developing treatments and the health care organizations that will ultimately be asked to pay for them. Last but not least, we also focus on the importance of communication with the general public, through patient advocate Brooke Ellison, who gives us an overview of a new book, “Stem Cell Hope” by TIME Magazine reporter Alice Park; and through outgoing ISSCR President Elaine Fuchs, who in her President's Note emphasizes the importance of active engagement with lay audiences to promote understanding and appreciation of stem cell research.In the context of a journal, the concept of communication is always relevant—it is our raison d'etre. We are therefore happy to be “communicating” a strong selection of new research findings in this issue, ranging from regulation of lung stem cells to suppression of aberrant transcripts in ESCs. Some papers were available online ahead of the issue date; others are newly available now. As always, you can find a summary of these studies and how they relate to each other on our Editors' Notes page. Last month, we partnered with our sister journal Neuron to bring you a focus on neural stem cells. This focus had two parts, the first being a collection of review articles and primary research papers in our May issue. Then, later in the month, Neuron published a special review feature covering a variety of different topics related to neural stem cells and adult neurogenesis. This month, Cell will also be publishing a collection of stem cell-related review articles. As I discussed last year (Sweet, 2010xSweet, D.J. Cell Stem Cell. 2010; 6: 493Abstract | Full Text | Full Text PDF | PubMed | Scopus (2)See all ReferencesSweet, 2010), Cell Stem Cell aims to follow the progress of the stem cell field toward clinical translation, and the most recent addition to our article type repertoire, “Clinical Progress,” fosters communication in that realm by presenting high-quality work that bridges the divide between basic research and clinical application. In this regard, we were pleased to see that last month Thomson Reuters highlighted Cell Stem Cell as a Rising Star in the field of Clinical Medicine, based on its citation record. Later this year, we hope to promote interaction in a different way, by cohosting a Cell Symposium on Stem Cell Programming and Reprogramming in Lisbon, Portugal, from December 8th to 10th. You can find information about the confirmed speakers and how to register to attend online at http://bit.ly/i9UZBs. Alternatively, if you prefer your missives about stem cell research in a more succinct form, you may want join our growing band of followers on Twitter (@CellStemCell).As I write this Editorial, we are making preparations for the ISSCR 2011 Annual Meeting. At the meeting itself, we are delighted to be partnering with the University Health Network – Toronto and the ISSCR to bring you a free half-day symposium to honor the scientific legacy of Ernest McCulloch (see Iscove, 2011xIscove, N. Cell Stem Cell. 2011; 8: 250–251Abstract | Full Text | Full Text PDF | PubMedSee all ReferencesIscove, 2011). All registered attendees for the ISSCR meeting are welcome to join us for this Focus Session, which will take place from 9:00 a.m. to 12:30 p.m. on Wednesday, June 15th. You can find more information about it and register your interest on the premeeting events page of the ISSCR website. Cell Press will have an exhibition booth at the meeting (#811), and we invite you to visit us to learn more about our various initiatives, including the special issues mentioned above, to meet Scientific Editors from Cell and Cell Stem Cell, and to enter to win an iPad 2 by connecting with us on Facebook. At the booth, we will also announce the results of our website-based “Best Paper” contest, so you can find out which of the six finalists was the most popular among our voters. In addition, you will be able to learn about an exciting new Cell Press tool designed to take authors “behind the scenes” in the publication process. When you pick up your delegate bag, you will see that it contains a copy of this issue of Cell Stem Cell (perhaps that is even where you found this Editorial). We are very grateful to Stemgent for providing the sponsorship that made it possible for us to distribute these journal copies. Stemgent focuses on developing cutting-edge products for the stem cell community, including a new mRNA-based reprogramming protocol based on a paper that Cell Stem Cell published last year (Warren et al., 2010xWarren, L., Manos, P.D., Ahfeldt, T., Loh, Y.-H., Li, H., Lau, F., Ebina, W., Mandal, P.K., Smith, Z.D., Meissner, A. et al. Cell Stem Cell. 2010; 7: 618–630Abstract | Full Text | Full Text PDF | PubMed | Scopus (1007)See all ReferencesWarren et al., 2010).In closing, I'd like to offer congratulations in advance to Robert Blelloch for receiving the ISSCR Outstanding Young Investigator Award this year, and to the winners of two new awards: Kazutoshi Takahashi and Shinya Yamanaka, receiving the McEwen Centre Award for Innovation, and Robert Klein, receiving the Public Service Award. As always, I look forward to communicating with as many of you as possible during the course of the ISSCR meeting, and of course to hearing about all of the latest and best research. See you there!

It's easy to be excited about stem cell research. Even setting aside the sometimes hyperbolic coverage in the mainstream media, it is clear from what we already know about the properties and pervasiveness of stem cells that they hold great promise for elucidating many aspects of basic biology and for potential therapeutic strategies. Indeed, some stem cell-based treatments are already part of mainstream medicine, most notably bone marrow transplants, which save lives on a regular basis. Others, such as treatment of neurodegenerative diseases or diabetes, are still more distant goals, but ones that seem increasingly realistic as our understanding grows. Recently, it has also become clear that our insights into stem cell biology may even help us devise more effective cancer therapies and better human disease models for the development of new pharmaceuticals. Underlying this advancing knowledge base is, of course, a burgeoning community of stem cell researchers, producing a rapidly expanding body of work that needs to be reviewed and distributed. Mirroring the trend, in the 5 years since it was founded the International Society for Stem Cell Research (ISSCR) has developed into a major international scientific organization. This is the energizing backdrop against which we are proud to introduce the latest addition to the Cell Press family of journals, Cell Stem Cell.The overall aim of Cell Stem Cell is to provide a forum for the dissemination of important new information about stem cell research. The publication topics will range from fundamental advances in our understanding of stem cell biology, in a wide range of organisms, to new findings of direct clinical relevance. Like all Cell Press journals, we will have a strong focus on high-quality research articles, as exemplified by the five papers included in this inaugural issue. They cover topics ranging from regulation of pluripotency to age-related decline, and I hope you will enjoy reading them. Going forward, we will publish standard and short research Article formats plus Resource articles describing technical advances or other information sources that will be of broad interest to the stem cell community. Each issue of Cell Stem Cell will also feature a wide variety of review material. The review section will cover current research topics, as illustrated by the article from Shinya Yamanaka in this issue, and will also frequently include contributions about ethical and policy issues relating to stem cell research. Initiating this aspect of our coverage are Commentary articles from Anne McLaren and Lord Robert Winston, two widely respected researchers from the UK who have played prominent roles in ethical and policy discussions related to stem cells. For more information about the articles featured in this issue, plus our online comment forum relating to the history of the term “stem cell,” see the Editors' Notes page that follows the Table of Contents.As editors and publishers, we consider many factors when making a decision to launch a new journal, but the most prominent by far is whether there is an indication from researchers that a new communication platform is needed. The path that led us to Cell Stem Cell involved something of a “meeting of minds” between Cell Press and the stem cell research community, as represented by the ISSCR. At Cell Press, we had observed the explosive growth of the stem cell field and the resulting rapid increase in the number of papers being published. At the same time, the society's members had indicated through a survey that they would like to see it initiate a new journal to serve the stem cell research community. Based on this information and feedback from a wide range of stem cell researchers, we and the ISSCR both concluded that the field would benefit greatly from a new high-quality forum for stem cell research, setting the stage for the launch of Cell Stem Cell. We chose the name Cell Stem Cell to provide a clear association with the Cell family of journals, to be clearly distinct from existing publications, and to encapsulate the intended aim of covering the entire field of stem cell biology. As for all Cell Press journals, access to Cell Stem Cell content will be free online from one year after publication. On the Cell Stem Cell website (http://www.cellstemcell.com), we are also featuring free access to a selection of stem cell papers published in other Cell Press journals and will post new articles online ahead of issue dates.We are delighted that the ISSCR has chosen to endorse Cell Stem Cell as its official affiliated journal. This is an unprecedented relationship for a Cell Press journal, so it merits some clarification. Like most other Cell Press journals, Cell Stem Cell will be run by an in-house team of scientific editors who will determine the content in terms of the research manuscripts and the review material in the journal. As respected researchers in the field, the ISSCR leadership will contribute to the peer review process for this material in the same way as other reviewers and Editorial Board members. In addition, in a feature that is unique to Cell Stem Cell, there will be a special dedicated section in the journal with content provided by the society. This section will provide a forum for the ISSCR to publish information that it would like to distribute to its members and the broader scientific community, including, for example, messages from the President, policy statements, and the results of committee discussions. In this issue, the ISSCR section includes a President's Note from Paul Simmons, giving his perspective on stem cell research from his time as ISSCR president, and a Committee Forum article from Douglas Sipp, the Chair of the International Committee, on the society's international scope. The articles that are provided by the ISSCR are clearly delineated in the journal by both the article header and the colored tab at the top of the page: green for editorial review material, tan for the society section, and blue for research articles. Overall, the affiliation agreement between Cell Stem Cell and the ISSCR is one of mutual support between two independent organizations. As part of the agreement, ISSCR members will receive a substantial discount on personal subscriptions to the journal. Also, although this inaugural issue of Cell Stem Cell is dated July 2007, it was published early for distribution to the attendees at the ISSCR annual meeting in Cairns, Australia, which runs from June 17th to 20th.Despite the excitement that surrounds our vision for this new journal, it would be somewhat disingenuous not to acknowledge that the stem cell field has produced perhaps more than its fair share of controversial publications in recent years. At Cell Stem Cell, we recognize our responsibility to make all reasonable efforts to ensure the veracity of the information that we publish. We will therefore, of course, subject all research articles published in Cell Stem Cell to rigorous peer review and hold authors to high standards in terms of documentation and presentation of their data. In the spirit of open communication, we will be happy to receive informative Correspondence articles about papers we have published, and we will have a Matters Arising format for challenges to published papers should the need occur. Furthermore, we will occasionally publish articles that investigate a controversial issue but lead to a negative conclusion, as we appreciate that such studies, if conducted rigorously, can be important for the ongoing progress of the field.The in-house editorial team of Cell Stem Cell will comprise three scientists. As the Editor, I come to Cell Stem Cell with over 10 years of editorial experience and have been at Cell Press since 1999. During my tenure here I have worked as a scientific editor on Cell, Molecular Cell, and Developmental Cell, and I have been the Editor of Developmental Cell since 2003. Before becoming an editor, I received my PhD at the MRC-LMB in Cambridge, UK, and was a postdoctoral fellow at The Scripps Research Institute in La Jolla, CA. I am joined by Heather Fleming, who as the Reviews Editor is responsible for organizing the review and opinion material in each issue. Heather joined us from a postdoctoral position at Massachusetts General Hospital in Boston and before that did graduate work at the Ontario Cancer Institute. The third member of the team will be Christina Lilliehook, who will be joining us as a Scientific Editor later this summer from the University of Rochester, following postdoctoral work at the Weill Medical College of Cornell University and graduate school at Mount Sinai School of Medicine. I am extremely grateful for the advice and support provided by the ISSCR, and particularly the Publications Committee, who formed the Cell Stem Cell ISSCR Advisory Committee and have participated actively in planning the journal. Last, but most definitely not least, I also want to express my appreciation for the support and assistance provided by the distinguished members of the Editorial Board, who are generous with their time in assessing submissions and helping to determine appropriate publication standards.Support and development of the field is the underlying goal of any journal, and Cell Stem Cell is no exception. Currently the stem cell field has tremendous momentum and is the focus of great anticipation within the research community and beyond. We hope you will enjoy reading and contributing to Cell Stem Cell, or CSC as we sometimes call it, and that with your input we can play a part in ensuring that this exciting area of biology fulfils its remarkable potential.

Gupta and colleagues highlight recent work, including their own, that suggested based on lineage tracing that mural cells are adipogenic, contrasting with the conclusions of a recent Cell Stem Cell paper.

Although spermatogonial stem cell niches have been defined in lower organisms, their definitive localization in mammalian seminiferous tubules has been elusive. In a recent Science paper, Yoshida et al. (2007) elegantly demonstrated a vascular and interstitial tissue-associated niche for undifferentiated spermatogonia in the mouse.

Summary In a recent Nature Cell Biology paper, Taddei et al. (2008) reveal that deletion of β1 integrin from K5-expressing mammary epithelial basal cells specifically attenuates ductal stem cell activity, without dramatically altering the basal cell layer, or morphogenesis overall.

We launched Cell Stem Cell a year ago this month. In some ways, it's difficult to believe that a whole year has passed since our inaugural issue, but in others, particularly if considering the exciting advances in the stem cell field, it's equally hard to believe it has only been a year. To celebrate our anniversary, we have put together a special online feature providing free access to a selection of some of our most popular articles. This feature is divided into three sections: one for research articles, one for our range of other formats, and one that is a collection of articles on iPS cells. We based our selections largely on download frequency and also on feedback from the research community. The chosen articles cover diverse topics such as cancer stem cells, miRNAs, and even stem cell patents. We hope you will enjoy this feature and that it will also illustrate the range and the quality of the articles we have been fortunate enough to publish in our first 12 issues.An anniversary is an opportune time to reflect on events that have occurred in the preceding year. In the stem cell field, there have been many interesting developments, and some of the most prominent have been in the area of iPS cells. It is important to remember, however, that iPS cells are only one facet of stem cell research and, at present, still a relatively small one. Indeed, as leaders in the field have pointed out, iPS cell technology does not reduce the need for embryonic stem cell research (Hyun et al., 2007xHyun, I., Hochedlinger, K., Jaenisch, R., and Yamanaka, S. Cell Stem Cell. 2007; 1: 367–368Abstract | Full Text | Full Text PDF | PubMed | Scopus (62)See all ReferencesHyun et al., 2007), let alone research in other areas of stem cell biology. There have been a number of other notable developments in the past year in several areas of stem cell research—too many to cover adequately in a brief Editorial. Practical, ethical, and political considerations also abound, and the regulatory climate is still changing rapidly around the world. Contributing to this progress over the past year has been a pleasure, and I look forward to the opportunities we will have to address important questions in future issues of Cell Stem Cell.With regard to Cell Stem Cell more specifically, we were delighted to receive the 2007 award for the “Best New Journal in Science, Technology and Medicine” from the Professional/Scholarly Publishing Division of the Association of American Publishers. From the outset, our intention has been that, in addition to publishing high-quality original papers, Cell Stem Cell will provide a forum for discussion of issues related to stem cell research. In pursuit of this goal, we have introduced new review material formats over the past year, including the “Protocol Review,” which analyzes the strengths and weaknesses of specific methodologies used in stem cell research. At the start of our second year, we are introducing two more: “Letter,” which will be used for succinct coverage of information pertinent to stem cell research, and “Forum,” which will provide a venue for expression of opinions and ideas relevant to the field. These formats will complement their longer, data-driven cousins, “Correspondence” and “Commentary,” respectively. The first example of the new “Forum” format appears in this issue (Sugarman, 2008xSugarman, J. Cell Stem Cell. 2008; 2: 529–533Abstract | Full Text | Full Text PDF | PubMed | Scopus (26)See all ReferencesSugarman, 2008); Jeremy Sugarman offers his perspective on ethical issues facing stem cell research in the wake of the iPS cell advances.Producing Cell Stem Cell over this past year would not have been possible without input from many different people, all of whom deserve our thanks. We very much appreciate the ISSCR's ongoing support of the journal, and we are happy to have been able to provide a venue for a number of society communications in the ISSCR section. The journal would not exist without the authors who entrusted their work to us and the reviewers who provided invaluable advice that helped us maintain high standards. Our Editorial Board members played a key role in this process, as did a number of other experts in the field. This month, we are delighted to welcome 12 new members to our advisory Editorial Board. Behind the scenes at Cell Press, many different people have worked on the print and electronic production of Cell Stem Cell. Also, for this issue in particular, I am very grateful to BD Biosciences for sponsorship support that has enabled us to provide a free copy of the journal for all delegates at the 2008 ISSCR meeting in Philadelphia. Together with the other members of the Cell Stem Cell editorial team—Heather Fleming and Christina Lilliehook—I look forward seeing a number of you there and to hearing from even more of you in the coming year.

In honor of the Cell Symposia series conference on Stem Cell Programming and Reprogramming taking place in Lisbon on December 8–10, this month's issue contains a special focus on reprogramming. Our Review and Perspective articles both come from speakers at the meeting. Thomas Graf outlines a broad range of discoveries dating back as far as 1951 that provided the backdrop for our current understanding of reprogramming both to pluripotency and across lineages. Some of the findings he discusses had a somewhat indirect, yet important, influence, whereas others served to provide the conceptual foundation on which transcription-factor-based reprogramming was built. Marius Wernig and his colleagues focus more on recent events, with a discussion of the latest advances in reprogramming somatic cells directly into neuronal cells of various different “flavors.” In addition, they lay out their views on guidelines and benchmarks for characterizing induced neuronal cells, based to a significant extent on existing standards for neuronal differentiation of pluripotent cells. Two of the research papers also provide insights into reprogramming, both focused on pluripotency. One, from the Pei lab, makes progress in understanding the chromatin-based mechanisms that underlie reprogramming by showing that the histone demethylases Jhdm1a/1b promote the process via demethylation of H3K36me2/3 and interface with both senescence and miRNA-based pathways. These demethylases also function downstream of vitamin C, which the same group showed previously enhances reprogramming. Rudolf Jaenisch's group present a different point, by showing that quite subtle differences in the stoichiometry of reprogramming factors can have a significant effect on the properties of the resulting reprogrammed cells. As the field continues to discuss issues related to the “quality” of reprogrammed cells, this paper introduces an additional parameter to take into account when devising reprogramming strategies.Broadening beyond science itself to policy and funding, this issue also features four Letters that give different perspectives on the recent European Court of Justice ruling regarding the patentability of embryo-derived human cells. Ian Wilmut voices many of the concerns that have been raised by the scientific community about the likely impact on the progress of research. Alan Trounson and colleagues from CIRM provide insights based on their experiences of funding translational research. James Lawford Davies and Alex Denoon are patent lawyers who specialize in life science and biotechnology, and they argue that, while certainly not beneficial to the field, the effects of the ruling on stem cell research may be more limited than has been suggested. Last but not least, Katja Triller Vrtovec and Christopher Scott discuss the likely implications for the patenting of pluripotent cells more broadly, particularly iPSCs. This discussion is especially pertinent given the geographical location of our conference, as many of the European scientists presenting and attending will still be digesting the ruling and considering the potential implications for their research programs. The costs associated with translating stem cell research were also of course brought into sharp focus recently by the decision by Geron to discontinue its pioneering spinal cord injury trial.The Cell Symposia Stem Cell Programming and Reprogramming meeting is part of the broader Cell Symposia conference series that Cell Press started last year. These meetings are relatively small and are designed to offer numerous opportunities for dialogue and discussion among participants, both during the sessions themselves and at a dedicated conference dinner that gives an additional avenue for interaction with the invited speakers. The topics we covered this year in the Symposia were varied, ranging from regulatory RNAs to autism; the same will be true for next year's series too, so keep an eye out for the announcements. All of the organizers of Cell Symposia Stem Cell Programming and Reprogramming are looking forward to meeting authors and readers later this month in Lisbon. We hope to see you there. However, if you are not able to make it, we hope you will instead enjoy the updates on various different aspects of reprogramming that appear in this issue, plus of course the broad range of stem cell topics covered by the rest of the articles, and we hope to see you in person elsewhere in the near future.

Early clinical trials designed to treat Parkinson's disease by transplantation of fetal tissue containing dopamine neuron precursors yielded promising results, but the approach retains several limitations. Multiple recent papers describe longer-term outcomes in these patients, and two additional studies offer novel approaches that may lead to autologous sources of transplantable dopamine neurons.

Every week, I am asked whether a family should take their loved one with an incurable disease to clinics that promise cures with supposed stem cell therapies. Usually, the costs for such therapies are in the tens of thousands of dollars. When I go to the websites of the providers, usually very slick, the therapies are often transplantation of tissue or umbilical cord stem cells for a variety of nonhematopoietic or nonmesenchymal disorders (claiming transdifferentiation), or even claim to be ESC therapies. I tell those that ask that there is no scientific basis for such transdifferentiation to date and no approved therapies using ESCs. If an enquirer is in the biomedical field, I remind him/her that there is now a pretty good operational way to determine whether a phenomenon, such as transdifferentiation, is real:(1)The scientific basis (e.g., of transdifferentiation) must be published in a peer-reviewed journal, but that is not enough.(2)Several independent laboratories should have confirmed and published in peer-reviewed journals that the findings as first published are reproducible, but that is not enough.(3)The principle that underlies the discovery (e.g., transdifferentiation) is so robust that any way you approach the issue, the discovery is validated, but that is not enough when therapeutic cell therapies are the objective.(4)The regeneration of tissues is rapid, robust, tissue-appropriate, and curative, not simply rare cells of uncertain origin.But these are not issues the lay public calling for the cures promised can judge alone. My own advice is that they should attempt to obtain the following from the stem cell companies or clinics before they agree to a therapy:(1)The provider must be able to send peer-reviewed papers from independent practitioners that establish the therapy as possible.(2)The provider must send evidence of approval from an independent committee, such as an institutional review board (a document from the clinical entity where the therapy is being practiced that shows the steps taken to protect the patient and justifying the experimental or approved therapy for their specific disease).(3)The provider must send a document from an agency equivalent to the Food and Drug Administration showing the approval of the experiment or the therapy for human subjects with their disease.I advise them that without all three, they must assume they are receiving an unproven therapy and that the patient is in danger of risking their life or health, of losing their money, of being away needlessly from home, family, and friends, and of course, of not being therapeutically improved.Over the past 2 years, the ISSCR has taken further steps to support the responsible translation of stem cell research to the clinic, releasing the Guidelines for the Clinical Translation of Stem Cells and accompanying Patient Handbook on Stem Cell Therapies (www.isscr.org/clinical_trans). As President of the ISSCR, I propose that we develop a website and occasional press alert naming as unproven stem cell therapies where providers of so-called “therapies” cannot supply to the ISSCR, within 60 days of request, evidence of rigorous and independent scientific and ethical review along the lines of what I recommend patients seek.We should be aware that the entities that cannot prove safety and efficacy are at one extreme of an unfortunate continuum that has, at the other end, proven therapies. We must all be cautious in our own enthusiasms and also how we define the minimum criteria required to achieve nonlisting on the site. We will not be a judge of approved therapies. I hope you agree with me on this subject, and I welcome your comments on this proposal either way.I ask for your understanding of this long introduction to a short presidency. I felt it was important to establish stem cell biology as an independent field, to establish our research as central to the development of regenerative medicine and new types of cancer therapies, to try to summarize the politics of stem cell policies clearly, and to find some way to keep our legitimate efforts separable and separate from the charlatans who compromise the safety of citizens in need of hope and cure and ultimately the promise of the field.

NFAT proteins are calcium-regulated transcription factors that play a critical role during the timing and activation of many vertebrate tissues. A recent paper in Cell (Horsley et al., 2008) demonstrates a role of the calcineurin-NFAT-CDK4 pathway in maintaining hair follicle stem cell quiescence. “Knowledge of the hair cycles and their control will undoubtedly give needed insight into many complicated growth processes of other body structures which are not at present well understood.”—Earl O. Butcher (Butcher, 1934)