Na+/H+ exchangers (NHE) of mammalian cells are plasma membrane intrinsic proteins mediating exchange of N+ and H+ ions in various tissues. The NHE catalyzes the electroneural transport of extracellular Na+ for intracellular H+. They play a major role in regulation of intracellular pH (pHi) in addition to trans-cellular absorption of Na+, cell volume regulation and possibly in cell proliferation. These primary functions of the Na+/H+ exchanger have been related to many pathophysiological states, include hypertension, organ growth and hypertrophy, regression of cancer and renal intestinal disorders. At least 7 NHE isoforms (NHE1-7) have been cloned so far. They are all similar in their primary structure and predicted to have 10-12 transmembrane domains. The C-terminal domain of NHEs are predicted to be intracellular. NHE7 (human 725 aa, chromosome Xp11.4) is ubiquitously expressed, and predominantly localizes to the trans-golgi network. NHE7 mediates the influx of Na+ or K+ in exchange for H+. It is ~70% related to NHE6 but relatively less (~25%) homologous with other NHEs.