Dr. Jerry L. Spivak Johns is a graduate of Cornell University Medical College and received training in internal medicine, hematology, and oncology at the Johns Hopkins Hospital, New York Hospital, and the National Cancer Institute. Board-certified in Internal Medicine and Hematology, he was Director of the Hematology Division at Johns Hopkins from 1980 to 1992, and Director of the Johns Hopkins Center for Chronic Myeloproliferative Disorders for the past 20 years. His research and clinical interests involve the pathogenesis, diagnosis, and management of the myeloproliferative neoplasms, polycythemia vera, primary myelofibrosis, essential thrombocytosis, and, in particular, hematopoietic stem cell behavior in these disorders.