The genetics of MS is complex; in recent GWASs, several HLA and over 100 non-HLA genes have been associated with the disease, with the DRB1*15:01 within the extended HLA(-DQB1*06:02, -DQA1*01:02, -DRB1*15:01, -DRB5* 01:01) haplotype (“HLA-DR15” haplotype thereafter) bearing the strongest association to MS (4, 15, 16). The gene discussed is HLA-DRB1; the disease is myeloid sarcoma.