IFNB1 and myeloid sarcoma: It is assumed that the effect of IFN-β is principally mediated by the type I IFN response pathway and not by major histocompatibility complex class II molecules that makes the lack of an impact of HLA DRB1*1501 on IFN-β response.4, 9Several investigations approve the downregulation of IFN-β production in MS patients.