CXCL12 and malignant colon neoplasm: The mechanism of colon cancer progression is relate to intestinal bacteria dysbiosis, and the drug pair ACE might improve the diversity and abundance of the related gut microbiota, in turn to increase the content level of SCFAs such as propionic acid and butyric acid, which further mediate intestinal SDF-1/CXCR4 signalling pathway to repair the integrity of the intestinal barrier, decrease Cyclin D1 and C-myc expressions, eventually inhibiting the growth and metastasis of colon cancer (Figure 7).