PPP1R12C and progressive familial intrahepatic cholestasis type 2: Therefore, we chose to target the AAVS1 site for the insertion ofABCB11, a bile acid transporter which is defective in progressive familial intra hepatic cholestasis type-2 (PFIC-2), a lethal disease of children where cytotoxic bile salts accumulate inside hepatocytes killing them and eventually the patient.