 Patients needing a hematopoietic cell transplant but who lack a suitably matched donor in their family can search the "Be The Match Registry" for a matched unrelated donor or cord blood unit.Hematopoietic cells are used to transplant patients with life-threatening disorders such as leukemia, lymphoma, aplastic anemia, as well as certain immune system and metabolic disorders.Hematopoietic cells can come from bone marrow, umbilical cord blood, or the circulating blood (peripheral blood stem cells (PBSCs)).