PKD2 and autosomal dominant polycystic kidney disease: Loss-of-function mutations in TRPP2 leads to autosomal dominant polycystic kidney disease (ADPKD) via promoting cell proliferation and fluid secretion, while tumor necrosis factor-α- (TNF-α-) mediated suppression of TRPP2 accelerates Hep-2 cell (a cell line originating from human laryngeal squamous cell carcinoma) proliferation [10, 11].