This is probably due to the liver cirrhosis in these patients, leading to an inadequate bile flow, leakage of bile and reversed transport of bile acids and intermediates from liver to plasma by the cholestasis-induced membrane transporters MRP3, MRP4 and OSTα/β in the hepatocyte basolateral plasma membrane (Halilbasic et al 2013). This evidence concerns the gene ABCC4 and cirrhosis of liver.