Th17 cells are potent inducers of tissue inflammation, and dysregulated expression of IL-17 appears to initiate organ-specific autoimmunity; this has been best characterized in mouse models of colitis [10], experimental autoimmune encephalomyelitis (EAE) [11,12], rheumatoid arthritis [13] and autoimmune myocarditis [14]. The gene discussed is IL17A; the disease is Autoimmunity.