IL17A and autoimmune disease: The evaluated cytokines can be classified into three broad groups: the proinflammatory Th-1 cytokines: IL-2, IFN-γ, and TNF-α; the counterbalancing Th-2 cytokines: IL-4, IL-5, IL-10, and IL-13; and the Th-17 cytokine IL-17A, which is actively involved in several autoimmune diseases including MS [21].