CD4 and autoimmune disease: Notably, IL-23 is part of the innate immunity (produced mainly by dendritic cells and macrophages) and promotes the expansion of CD4+ T helper (Th)-cells secreting IL-17 (Th17) which is a potent pro-inflammatory cytokine [47] IL-17 plays a dominant role in MS (and EAE) and in several other autoimmune diseases [48].