HLA-DRB1 and myeloid sarcoma: We evaluated the associations of the 4-digit HLA alleles with MS risk and found the most significant association to be with HLA-DRB1*15:01 (P = 2.1 × 10−5, odds ratio [OR] = 3.44, 95% confidence interval [95% CI] = 1.95–6.07; Table 2).