Dan L. Longo is professor of medicine at Harvard Medical School in the division of hematology at Brigham and Women’s Hospital and Deputy Editor of the New England Journal of Medicine. He is a Master of the American College of Physicians and is a member of the American Society of Clinical Investigation and the Association of American Physicians. He has been active in research on the treatment of malignant lymphoma including new treatments targeting CD30, CD40, HLA Class II molecules and immunoglobulin idiotype. His laboratory work has focused in part on the regulation of lymphocyte proliferation, NK cell effects on hematopoiesis, and tumor-induced immunosuppression. He is the Section Editor of the Malignant hematological diseases section for BMC Hematology. In this interview, he explains how he first became interested in hematology and gives his personal view on the recent progress and future challenges of the hematological cancer field in particular.