CADM1 and carcinoma of esophagus: Many studies have shown that CADM1, as a tumor-suppressor gene, is associated with inhibition of cell proliferation, as well as invasion and induction of apoptosis in various tumor cells, including the non-small cell lung cancer A549 cell line (26), human esophageal carcinoma Eca109 cells (27), and a hepatocellular carcinoma cell line (28).