James Zwiebel received the MD degree from the Mount Sinai School of Medicine, where he also completed his residency training in internal medicine. Following a clinical fellowship in hematology and oncology at the George Washington University Medical Center and research fellowships at both the National Cancer Institute and the National Heart Lung and Blood Institute, he continued his laboratory work on cancer gene therapy as a member of the faculty at Lombardi Cancer Center of the Georgetown University Medical Center, where he also practiced hematology and oncology. Dr. Zwiebel is now Chief of the Investigational Drug Branch in the Cancer Therapy Evaluation Program of the NCI, where he and his colleagues work with investigators and industry to bring promising new cancer therapies into the clinic.