The induction of IL-27 during this infection could be a direct response to SeV [32] or may represent a secondary response to the SeV-induced production of type I interferons [32, 34] as during experimental autoimmune encephalitis and multiple sclerosis, the ability of type I IFNs to promote IL-27 is linked to their clinical efficacy [35]. This evidence concerns the gene IL27 and multiple sclerosis.