- Donors must be a 6/6 HLA-matched related donors, defined by Class I (HLA-A and -B) intermediate resolution or high resolution DNA-based typing and Class II (HLA-DRBI) at high resolution DNA-based typing (but not monozygotic twins) OR an 8/8 HLA-A, -B, -C, and -DRB1 at high resolution DNA-based typing matched unrelated donor identified through the National Marrow Donor Program (NMDP)/Be The Match. Donors must meet institutional or NMDP/Be The Match selection criteria; there is no age restriction for sibling donors.