HLA-DRB1 and myeloid sarcoma: Severely immunodeficient NOD.Cg-B2mem1Tac Prkdcscid Il2rgtm1Sug/JicTac (B2m-NOG) mice, which lack murine B, T, and NK cells and murine major histocompatibility class I molecules and have defective innate immune responses, were transplanted with PBMC from HLA-DRB1-genotyped MS patients and healthy donors.