HLA-DRB1 and myeloid sarcoma: A significant difference between MS patients and healthy individuals in the following HLA-DRB1 class II alleles were observed: HLA-DRB1 * 03:01 (Pc =  0.01) and HLA-DRB1 * 04:01 (Pc =  0.004) are linked positively to MS, with a frequency of 19.2% and 5.4%, respectively, compared to the control group, 8.7% and 0%, respectively (Table 2).