IL17F and Autoimmunity: The differentiation of naïve T cells into pathogenic (α/β CD4+ T cells that express high levels of IL-23R, coproduce IL-17A and IFN-γ/GM-CSF and induce autoimmunity) or non-pathogenic (α/β CD4+ T cells that produce IL-17A and IL-17F but do not induce autoimmunity) Th17 cells is influenced by DC-derived cytokines.