Various degrees of methylation in the CDH1 promoter CpG islands and the consequent loss of E-cadherin expression were reported in many tumor tissues, such as cervical carcinoma 17, prostate carcinoma 18, malignant melanoma 19, non-small cell lung carcinoma 20, liver carcinoma 21, esophageal cancer 22, and GC 23. This evidence concerns the gene CDH1 and gastric cancer.