The proliferation assay results showed that CXCL12 enhanced proliferation of the three colon cancer cell lines in a dose-dependent manner (*p < 0.01, **p < 0.05 compared with control, Fig. 4a); The addition of LY294002, an inhibitor of PI3K, inhibited the proliferation of cancer cells (*p < 0.01, **p < 0.05 compared with control, Fig. 4b). This evidence concerns the gene CXCL12 and cancer.