HLA-DRB1 and myeloid sarcoma: As indicated by the researchers, one of the most important genetic determinants of the development of MS, determining both the predisposition or resistance to the disease, is the HLA class II gene DRB1 (haplotype HLA-DRB5*0101-HLA-DRB1*1501-HLA-DQA1*0102 -HLA-DQB1)*0602).