John Tisdale received his M.D. degree from the Medical University of South Carolina in Charleston in 1990. He completed an internal medicine and chief residency at Vanderbilt University Medical Center in Nashville and then trained in hematology in the Hematology Branch, National Heart, Lung and Blood Institute (NHLBI), where he served as a postdoctoral fellow. He joined the Molecular and Clinical Hematology Branch of NHLBI in 1998 and is currently a senior investigator in that lab. His group focuses on bone marrow stem cell-based approaches to treat sickle cell disease. The work focuses on the development of methods for transplantation of either normal donor-derived or genetically modified patient-derived bone marrow stem cells.