The promoter region of CDH1 is commonly hypermethylated in cases of diffuse gastric cancer, which is closely linked to the downregulation of CDH1 protein expression; moreover, clinical evidence has demonstrated that the downregulation of CDH1 protein expression leads to a more aggressive phenotype of gastric cancer and a worsened prognosis for patients with gastric cancer [81,82]. Here, CDH1 is linked to gastric cancer.