IL17A and myeloid sarcoma: The pathogenesis of MS is characterized by the presence of pro-inflammatory self-reactive T cells, mainly T-helper 1 (Th1), Th17, and Th22 cells, producing interferon gamma (IFN-γ), interleukin 17 (IL-17) and IL-22, and a deficit of regulatory T cells (Tregs), which lose the ability to suppress the autoreactive response (7–9).