This application is for renewal for a third cycle of a Predoctoral Training Program in Developmental Biology, Stem Cells, and Regeneration at the University of Southern California (USC). This training program has both benefitted from and contributed to the dramatic growth of stem cell biology and regenerative medicine research at USC Keck School of Medicine. The presence of a dedicated Department of Stem Cell Biology and Regenerative Medicine that has been actively recruiting new faculty, a highly successful PhD Program in Development, Stem Cells, and Regeneration (DSR) that now averages ~15 new entering students per year, and a university-wide USC Stem Cell initiative makes for a highly dynamic, ideal training environment for students. The training program is designed to provide cohesive, structured training in developmental and stem cell biology, coupled with training-grant-specific courses and activities that provide in-depth exposure to clinical problems and advanced bioinformatics. Such a program will best train a future generation of scientists that wish to apply their foundational research in developmental and stem cell biology to the field of regenerative medicine. A unique strength of this training program is that it provides added value, beyond the DSR program, in the form of clinical exposure. Each trainee is paired with a Clinical Co-Mentor, who guides the student in learning about the diseases to which their primary research relates. Trainees take a T32-specific seminar class led by clinician scientists, as well as a hands-on workshop in USC’s new GMP facility that exposes students to manufacturing of clinical-grade stem cells and gene therapy reagents. This exposure of students to how stem cells can address unmet clinical needs is aided by close ties of USC with one of the largest public hospitals in the country, and the extensive participation of clinician-scientists in all aspects of the training program. Recently, we have also partnered with the Department of Quantitative and Computational Biology to offer specialized computational biology training, in direct response to feedback from trainees. During the previous four years of the training program, the 16 funded trainees have published 30 manuscripts in journals such as Cell Stem Cell, Developmental Cell, PNAS, Neuron, and PLoS Biology, and have received four NIH F31 fellowships. Of the 30 trainees since T32 inception, 16 have graduated and 13 remain in training. All graduates have remained in science-intensive positions, with 7 performing postdocs, 6 entering industry, 3 pursuing science policy and journalism, and 1 recently accepting a tenure-track assistant professorship at UCLA. From the first to second funding period, we have increased diversity in our program (12.5% to 25% URM), success of NIH F31s (2 to 4), and the number of students in the main DSR feeder program (~6 to ~15 per year), while decreasing time to degree (6.5 to 5.1 years). The students have hosted a major sy...