Previous studies reported [6, 7] that the increase in the number of TH17 cells in AIH was associated with the degree of liver fibrosis, and in vitro studies also confirmed that deficiencies in IL-17A and IL-17A receptors could reduce the liver fibrosis caused by CCl4 and bile duct ligation in mice [33]. The gene discussed is IL17RA; the disease is autoimmune hepatitis.