AQP4 and nonpapillary renal cell carcinoma: Among the twelve AQP family members, low mRNA expression of AQP1 (P = 5.3e-10), AQP3 (P = .014), AQP4 (P = .00025), AQP5 (P = .028), AQP7 (P = 8.8e-05) and AQP10 (P = .014) was associated with worse OS in ccRCC patients.