The evidence that IL-17-knockout (KO) mice are less prone to develop autoimmune diseases such as type 1 diabetes, collagen-induced arthritis, and experimental autoimmune encephalomyelitis [41, 47] raised the hypothesis that this cytokine, and therefore IL-17-producing cells, may also be involved in the pathogenesis of pSS. The gene discussed is IL17A; the disease is autoimmune disease.