ABCB11 and progressive familial intrahepatic cholestasis type 2: Abnormal expression or functional disturbance of BSEP results in a spectrum of cholestatic diseases including progressive familial intrahepatic cholestasis type 2 (PFIC2), benign recurrent intrahepatic cholestasis type 2 (BRIC2), drug-induced liver injury, and intrahepatic cholestasis of pregnancy [2–4].