These differentially expressed proteins included caveolin 1 (CAV1), cadherin 1 (CDH1), claudin 7 (CLDN7), cadherin 3 (CDH3), and PAR proteins, which were all 2-fold overexpressed in ESCC cell lines as compared to Het-1A cells (Supplementary Figure 1). This evidence concerns the gene CLDN7 and esophageal squamous cell carcinoma.