IFNB1 and myeloid sarcoma: It is well known that human leukocyte antigen (HLA) class II alleles on chromosome 6p21 play a major role in genetic predisposition to MS, mainly HLA-DR and DQ alleles (DRB1*1501, DRB5*0101, DQA1*0102, and DQB1*0602).8Some of studies validated the association of HLA DRB1*1501 with better response to GA but not IFN-β, and this impact is rather moderate.