IL17A and Autoimmunity: On the other hand, IL-17-producing γδ T cells have pathogenic roles in various inflammatory and autoimmune disorders (and animal models thereof), including collagen-induced arthritis (CIA) (33), experimental autoimmune encephalomyelitis (EAE) (8, 34–38), chronic granulomatous disease (39), uveitis (40), ischemic brain inflammation (41), colitis (42, 43), and psoriasis (44, 45).