SLC9A1 and cancer: Indeed, cancer progression through metastasis and development of treatment resistance have been reported sensitive to inhibition of Na+/H+ exchangers (Amith and Fliegel, 2017; Stock and Pedersen, 2017); however, several anti-cancer effects of pharmacologically inhibiting Na+/H+ exchange appear only partly pH-dependent (Boedtkjer et al., 2012; Loo et al., 2012; Schwab et al., 2012) and can be caused by NHE1-independent toxicity due to intracellular drug accumulation (Rolver et al., 2020).