- All candidates for this study must have a HLA (-A, -B, -C, -DR) identical sibling who is willing to donate bone marrow or primed blood stem cells or a 10/10 allele-matched unrelated donor or minor mismatches as per BMT SOP that allows Tacrolimus and Sirolimus to be given for GVH prophylaxis; all ABO blood group combinations of the donor/recipient are acceptable since even major ABO compatibilities can be dealt with by various techniques (red cell exchange or plasma exchange)