HLA-DRB1*0405 and HLA-DPB1*0301 were found to be MS susceptibility genes21, whereas HLA-DRB1*1602 and HLA-DPB1*0501 conferred susceptibility only to anti-AQP4 antibody-positive NMO22. The gene discussed is HLA-DRB1; the disease is myeloid sarcoma.