Steven R. Bauer, Ph.D., is the chief of the Cellular and Tissue Therapy Branch (CTTB), Division of Cellular and Gene Therapies in the Office of Tissues and Advanced Therapies at the Center for Biologics Evaluation and Research (CBER) in the U.S. Food and Drug Administration. As the chief of CTTB, Dr. Bauer supervises CBER scientific staff engaged in review of cell-based biological therapies, policy development in emerging areas of cellular therapies, and research relevant to their use in clinical trials. His current research focuses on mesenchymal stem cell biology and stromal cell–hematopoietic cell interactions that influence the development of lymphocytes. Dr. Bauer received his Ph.D. in biochemistry from the University of Maryland in 1986. From 1986 through 1991, Dr. Bauer was a scientific member of the Basel Institute for Immunology in Basel, Switzerland. In 1991, Dr. Bauer joined CBER's Division of Cellular and Gene Therapies.