SLC9A1 and neoplasm: Despite tumor cells having a high glycolytic rate that causes an increased intracellular proton production, the function of several proton extruders (such as NHE1, NBCs, or Hv1, to mention) that expel these protons, maintain their internal pH to generally stay within the range of normal physiological values (between 7.2 and 7.4, according to Webb et al., 2011.