IFN-β treatment of T cells from both MS patients and healthy controls decreased both their proliferative capacity as well as their ability to secrete IFN-γ [14], and the frequency of IFN-γ+ and IL-2+ peripheral blood mononuclear cells (PBMCs) was reduced in MS patients undergoing IFN-β treatment as compared to therapy naïve patients [56]. This evidence concerns the gene IFNB1 and myeloid sarcoma.