This additional Na+ influx would either lead to a slow and continuous increase in intracellular [Na+], resulting in cell death (the opposite of what we observed in the more acidic parts of the tumour), or it would lead to increased NKA activity in the more acidic parts of the tumour, to maintain a stable intracellular [Na+] and maintain cell viability. The gene discussed is TAC1; the disease is neoplasm.