AQP9 and cancer: Overall, several AQPs, including AQP1, AQP3, AQP4, AQP5, AQP8, and AQP9, have been suggested to transport H2O2, and their expression promotes cancer cell growth and migration (111, 118–127), However, solid data exist only for AQP3- mediated H2O2 transport as one of the key mechanisms for cancer cell migration.