ATP8B1 and progressive familial intrahepatic cholestasis type 1: The FIC1 gene (ATP8B1) encodes an ATPase, which is expressed not only in the liver and small intestine but also in pancreatic acinar cells, gastric pit epithelial cells, and cholangiocytes as well as in the inner ear; extrahepatic manifestations, such as diarrhoea, pancreatic disease, rickets, pneumonia, abnormal sweat tests, hearing impairment, and poor growth have been described in PFIC1 patients [2].