ARPKD is due to mutations in the Polycystic Kidney and Hepatic Disease 1 (PKHD1) gene, which encodes fibrocystin, and is localized to the primary cilium in the kidneys, liver, and pancreas, predominantly in the basal body of cilia present in renal tubular cells and biliary epithelial cells [57,58] (Figure 2). Here, PKHD1 is linked to autosomal recessive polycystic kidney disease.