Hematopoietic-Cell Transplantation at 50

September 12, 2007, marked the 50th anniversary of E. Donnall (Don) Thomas's initial report of a radical new approach to cancer treatment: radiation and chemotherapy followed by the intravenous infusion of bone marrow.1 That publication represented the beginning of a long series of laboratory and clinical investigations; more than a decade would pass before the procedure achieved its first successes. Yet Thomas's persistence in the face of criticism and clinical failure ultimately paid off in a new form of therapy that was used to treat approximately 50,000 people worldwide in 2006 (see timeline).Thomas's interest in the possibility of hematopoietic-cell . . .