In studies of MS and in the murine animal model of experimental autoimmune encephalomyelitis (EAE), the presence of VD has been correlated with increased expression of anti-inflammatory cytokines (IL-4; IL-10) and transforming growth factor β (TGF-β), a decrease in the expression of certain pro-inflammatory cytokines such as IL-12, IL-17, and IFN-γ [5], and modulation of the T cell response [6], thus highlighting its immunoregulatory role. The gene discussed is IL17A; the disease is myeloid sarcoma.