Hematopoietic stem cell transplantation (HSCT) is the transplantation of blood stem cells derived from the bone marrow (that is, bone marrow transplantation) or blood. Stem cell transplantation is a medical procedure in the fields of hematology and oncology, most often performed for people with diseases of the blood, bone marrow, or certain types of cancer. Stem cell transplantation was pioneered using bone-marrow-derived stem cells by a team at the Fred Hutchinson Cancer Research Center from the 1950s through the 1970s led by E. Donnall Thomas, whose work was later recognized with a Nobel Prize in Physiology and Medicine.Thomas' work showed that bone marrow cells infused intravenously could repopulate the bone marrow and produce new blood cells. His work also reduced the likelihood of developing a life-threatening complication called Graft-versus-host disease. With the availability of the stem cell growth factors GM-CSF and G-CSF, most hematopoeitic stem cell transplantation procedures are now performed using stem cells collected from the peripheral blood, rather than from the bone marrow.Collecting stem cells provides a bigger graft, and does not require that the donor be subjected to general anesthesia to collect the graft. Hematopoeitic stem cell transplantation remains a risky procedure with many possible complications; it has always been reserved for patients with life-threatening diseases. This book presents recent leading research in the field.