ABCB4 and progressive familial intrahepatic cholestasis: The variants responsible for the most common and known forms of PFIC, particularly the variants of ABCB4, have been linked to various heterogeneous cholestatic diseases [24]; these variants seem to be inherited through recessive inheritance in the case of PFIC, while less severe diseases like ICP or LPAC are likely to be inherited as autosomal dominant variations.