ABCB4 and Hepatic fibrosis: Moreover, polymorphisms such as rs2109505 (c.711A>T, p.I237=) in ABCB4 and rs2287622 (c.1331T>C, p.V444A) in ABCB11 are more prevalent in adult patients with idiopathic cholestasis than in healthy controls representing risk factors for the development of liver fibrosis [48].