Stem cell regulation is critical for tissue development and maintenance. Defects in stem cell regulatory mechanisms are thought to contribute to many diseases, including congenital diseases, cancer and diseases of aging; therefore, these mechanisms are of interest to a diverse audience. Recent stem cell meetings have tended to focus on the interface of stem cells and cancer, or on reprogramming. This has left the majority of stem cell biologists with fewer forums that focus on the basic mechanisms that regulate stem cell function. And yet critical advances are occurring that give glimpses of new molecular mechanisms that regulate stem cell and tissue homeostasis. The goal of this Keystone Symposia meeting is to identify new and common mechanisms governing stem cell function and differentiation across tissues and across species. To address this, the meeting is organized into sessions according to distinct modes of stem cell regulation, without regard to species, in a way that might highlight novel paradigms of regulation. Speakers will be chosen, first and foremost, based on research quality, and then to cover broad areas of stem cell research. The program for this meeting is highly likely to attract a wide variety of investigators, many of whom might not otherwise interact. The focus on stem cell regulation in general provides an umbrella under which speakers from different areas of research (e.g., developmental biology, tissue growth and homeostasis, regeneration, cancer and aging) are being brought together in an environment that is highly conducive to cross-talk.