According to DNA methylation profiles of gastric cancer cells and normal gastric cells from TCGA, we found that 5 genes have methylation change, including RUNX1 (P-value < 3.56☓10-1), ARHGDIB (P-value < 1.81☓10-1), PSME1 (P-value < 2.59☓10-1), GZMB (P-value < 1.79☓10-1), and RBM5 (P-value < 3.94☓10-1), and 2 genes have small methylation change including VAMP5 (P-value < 8.61☓10-1), POLG (P-value < 8.38☓10-1) between gastric cancer cells and normal gastric cells (Fig. 3). This evidence concerns the gene POLG and gastric cancer.