Transplantation of the cells from which the body develops blood cells. Such transplantation is being used for an increasing number of diseases, including certain cancers, anemias, immune deficiency, and genetic and metabolic disorders. The transplantation may be from the patient’s own body, autotransplantation, or from another person, allotransplantation. Sources of the transplant at this time may be bone marrow, blood, or umbilical cord blood.