PKD2 and autosomal dominant polycystic kidney disease: Formation of renal cysts is the hallmark of autosomal dominant polycystic kidney disease (ADPKD), which is the most common ciliopathy [4] and is mainly caused by mutations in the genes PKD1 and PKD2, which encode the proteins polycystin-1 (PC1) and polycystin-2 (PC2).