Previous studies have shown that IFN-β induces IL-10 production in monocytes in vitro [32,33], and numerous CSF and blood biomarker studies have linked high levels of IL10 gene expression or IL-10 protein in vivo to IFN-β treatment and to disease control in IFN-β-treated and untreated MS [18,33–41]. This evidence concerns the gene IFNB1 and myeloid sarcoma.