In breast cancer cells, Na+ influx mediated by non-inactivated Nav1.5 channels allosterically increases the activity of the Na+-H+ exchanger NHE1, thereby promoting the efflux of H+ and further increasing Na+ into cancer cells, subsequently alkalizing intracellular pH and reducing extracellular pH (Brisson L, et al., 2011). The gene discussed is SCN5A; the disease is breast cancer.