Two genes encode Na+-dependent Cl-/HCO3- exchangers; SLC4A8 (NDCBE1) and 10 (NCBE). SLC4A8 (NDCBE1) encodes a exchanger protein which mediates Na+:HCO3- transport with a stoichiometry of 1:2:1 (Na+/HCO3-/Cl-). This protein is highly expressed in brain and spine and moderately expressed in trachea, thyroid, and kidney (Amlal H et al, 1999). SLC4A10 (NCBE, NBCn2) encodes a Na+-driven Cl-/HCO3- exchanger protein (Parker MD et al, 2008). It transports extracellular Na+ and HCO3- into cells in exchange for intracellular Cl- and H+, thus raising the intracellular pH.