PKD2 and autosomal dominant polycystic kidney disease: The polycystin domains of TRPP3 share similar structural features and high degree of homology to PKD2 (also termed TRPP2)18,19,49, that together with PKD1 play crucial roles in autosomal dominant polycystic kidney disease (ADPKD), a common and potentially lethal disorder resulting in major renal disorders.