Th17 cells (CD3+CD4+IL-17+) which are part of the immune system and emerge next to Th1 (CD3+CD4+INF-y+) and Th2 cells (CD3+CD4+IL-4+) from naive T helper cells [13–16], play an important role in protection against pathogens and are importantly implicated in the pathogenesis of autoimmune disorders [17–21]. The gene discussed is IL17A; the disease is autoimmune disease.