HLA-DRB1 and myeloid sarcoma: Irízar et al. [23] reported a non-significant trend towards increased risk for MS in HLA-DRB1*15-positive subjects carrying rs7975232A or rs731236T alleles in a case-control study which included 325 HLA-DRB1*15-positive subjects (96 MS patients and 229 controls) and 110 HLA-DRB1*15-negative subjects (34 MS and 76 controls) genotyped for rs7975232, and 392 HLA-DRB1*15-positive subjects (122 MS patients and 270 controls) and 43 HLA-DRB1*15-negative subjects (11 MS and 32 controls) genotyped for rs731236.