Weimann et al. compared six immunohistochemical markers for the histologic diagnosis of neoplasia in Barrett’s esophagus [38]; however, they found that Claudin-2 staining was only focal and weak and did differ significantly between normal (5%), Barrett’s esophagus (2%), low- (5%) and high-grade dysplasia (7%) and EAC (16%). This evidence concerns the gene CLDN2 and esophageal adenocarcinoma.