IL17A and myeloid sarcoma: With respect to their functional phenotype, autoreactive CD4+ T cells in MS express T helper 1 (Th1; produce IFN-γ), Th1*- (produce IL-17 in addition to IFN-γ) or Th17- (express IL-17) phenotypes and furthermore markers that are important for brain homing such as VLA-4, and the chemokine receptors CXCR3 and CCR6 (30).