Mutations in genes encoding cholangiocyte ciliary-associated proteins, such as polycystin-1 and -2 and fibrocystin, cause biliary dysgenesis, hepatic fibrosis and cystogenesis in liver diseases such as Autosomal Dominant Polycystic Kidney Disease (ADPKD) and Autosomal Recessive PKD (ARPKD). This evidence concerns the gene PKD1 and autosomal dominant polycystic kidney disease.