ABCB4 and Cirrhosis: Histologically, PFIC3 is characterized by portal inflammation, fibrosis, progression to cirrhosis, and unlike PFIC2 (another type of progressive familial cholestasis characterized by mutations in the ABCB11 gene encoding BSEP), bile ducts are highly proliferative in PFIC3 (Oude Elferink and Paulusma, 2007).