ATP-binding cassette transporter sub-family B member 4 (ABCB4) is also known as multidrug resistance protein 3 (MDR3), despite not being able to confer drug resistance []. It is localised at the canalicular membrane of hepatocytes, and mediates the translocation of phosphatidylcholine into bile [].Mutation in the ABCB4 gene cause progressive familial intra-hepatic cholestasis type 3 (PFIC3), a rare disease characterised by an early onset of cholestasis that leads to cirrhosis and liver failure before adulthood [], and other rare cholestatic disorders [].
