There were metastatic sites in the lungs of the nude mice in the HCT116-Lv-Ctrl group, but no metastases were observed in the HCT116-Lv-TDG group (Figure 2F); that is, TDG overexpression inhibited the metastasis of human colon cancer cells in vivo. Here, TDG is linked to malignant colon neoplasm.