HLA-DRB1 and myeloid sarcoma: This contrasts with another study of the MHC in Hispanics and African Americans conducted by Chi et al. which reported association with MS at the same significance level for only HLA-DRB1*15:01 in Hispanics [12] and HLA-DRB1*15:01 and HLA-DRB1*03:01 in African Americans.