IL17A and myeloid sarcoma: T helper 1 (Th1) cells, characterized by the production of interferon-γ (IFN-γ), have been considered as the type of effector helper T cells that mediate the pathogenesis of MS; subsequently studies have indicated that interleukin 17 (IL-17)-producing T helper (Th17) cells are involved and play more important role in this pathogenesis than Th1 cells (Ogura et al., 2008; McGeachy et al., 2009; El-Behi et al., 2011; Lazarevic et al., 2011; Goldmann and Prinz, 2013; Martin et al., 2016).