The changes of pHi caused by Phx-3 in gastric cancer cells were not investigated until 2011 [53], when the effect of Phx-3, associated with NHE-1, on gastric cancer cells was investigated in terms of how they affected pHi, as well as with regard to the possible causal correlation between a decrease in pHi and the appearance apoptotic events. Here, SLC9A1 is linked to gastric cancer.