ATP8B1 and progressive familial intrahepatic cholestasis type 1: Mutations in ATP8B1 cause progressive familial intrahepatic cholestasis type 1 (PFIC1) and benign recurrent intrahepatic cholestasis type 1 (BRIC1) [133,134], two liver disorders which were first described by Clayton et al.[135] and Summerskill and Walshe [136] (reviewed in [110]).