SLC9A1 and neoplasm: Esomeprazole, Lansoprazole (vacuolar-ATPase inhibitors), Amiloride and Cariporide (sodium-hydrogen exchanger-1, NHE-1 inhibitors) were assayed for cell viability and extracellular medium pH measurements to monitor the therapeutic effect on tumor cells incubated for 24 or 48 h with these drugs, both in normoxia and hypoxia.