Adherens junctions-associated protein-1 (AJAP1) is a type 1 transmembrane protein that is located and interacts with the E-Cadherin–Catenin complex, which is frequently lost or epigenetically silenced in ESCC cells because of promoter hypermethylation in polarised epithelial cells. This evidence concerns the gene CDH1 and esophageal squamous cell carcinoma.