Mutations in one of two ciliary proteins, PC-1 (encoded by PKD1) and PC-2 (also known as TRPP1 and encoded by PKD2), account for 85% and 15% of ADPKD-causing mutations, respectively (Harris and Torres, 2009; Cornec-Le Gall et al., 2014). The gene discussed is PKD2; the disease is autosomal dominant polycystic kidney disease.