Increased expression of IL-17 family members and the presence of IL-17-producing cells have been reported to relate with Crohn’s disease and ulcerative colitis, while IL-17F and IL-17RA have an increased susceptibility to commensal fungi mainly manifesting as mucocutaneous candidiasis though enhanced expression of IL-17 family members and the IL-17secretion [41]. The gene discussed is IL17A; the disease is ulcerative colitis.