Ca2+ has proven to be a universal signaling molecule in excitable and non-excitable cells. However, being that its intracellular concentration is 1000 time lower than the extracellular milieu, it is important for the cell to keep this ratio for proper function. NCX, a Na+/Ca2+ exchanger is responsible for most of the efflux of Ca2+ out from the cell1-3. The NCX transporter is a member of the SLC8 family of solute carriers which in turn belong to the CaCA superfamily. NCX-3 is expressed in skeletal muscle and in some regions of the brain and undergoes alternative splicing in a similar fashion to that of NCX-11
