Over the following decades, the mechanisms of an altered pHi climate in many cancers including esophageal, gastric and colonic cancer, the consequences for malignant proliferation, as well as the importance of the NHE1 isoform in the maintenance of malignant growth and the potential to influence malignant growth by manipulating NHE1 activity, was intensely studied, as well as reviewed (Reshkin et al., 2000; Fang et al., 2008; Liu et al., 2008; Boedtkjer et al., 2012; Sharma et al., 2015; Parks et al., 2017; Stock and Pedersen, 2017; Cao et al., 2019; Cardone et al., 2019; Hu et al., 2021). The gene discussed is SLC9A1; the disease is cancer.