For instance, the H. pylori cytotoxin-associated gene A (CagA) protein not only promotes hypermethylation of tumor-suppressor genes like CDKN2A but also interacts with E-cadherin, disrupting β-catenin signaling in epithelial cells, thereby contributing to gastric cancer tumorigenesis (Yong et al., 2015). This evidence concerns the gene CDH1 and gastric cancer.