A defective copy of either PKD1 or PKD2, which encodes polycystin-1 (PC1) or polycystin-2 (PC2), is inherited by individuals with ADPKD, in which PC1 and PC2 are released in urinary exosome-like vesicles (uELVs), and PC1 is present in a fragmented form and may bind with PC2. The gene discussed is PKD2; the disease is autosomal dominant polycystic kidney disease.