SLC4A2 and biliary liver cirrhosis: SLC4A2 knockdown experiments in mammalian cholangiocytes have implicated AE2 as the main effector in biliary HCO3− secretion4 and furthermore, SLC4A2 knockdown mice exhibited typical symptoms of primary biliary cholangitis (PBC), including generation of antimitochondrial antibodies (AMA), portal inflammation and damaged interlobular bile ducts9–11.