SLC9A1 and esophageal adenocarcinoma: Goldman et al. (2010) reported that, compared to its expression in normal esophageal epithelium and normal esophageal cells, NHE1 is highly expressed not only in biopsies from patients with Barrett’s esophagus, but also in the CP-A cell line derived from Barrett’s esophagus. Due to the frequent acid exposure of esophageal cells over a long period, the progressive intestinal metaplasia occurring in Barrett’s esophagus may represent an adaptive process (Ostrowski et al., 2007), which is accompanied by an increase in NHE1 expression in order to defend intracellular pH.