Abstract
Hematopoietic stem-cell transplantation, which is used to treat both malignant and nonmalignant conditions, was first conceived more than 50 years ago, but problems associated with transplanting a nonsolid organ and modulating the immune response had to be solved before the procedure could be used clinically. This review summarizes background information about hematopoietic stem-cell transplantation and discusses the current role of the procedure.