CXCR4 has been demonstrated to be a prognostic marker associated with numerous cancers, such as breast, prostate, lung, and colon cancers, where it promotes metastasis, angiogenesis, and tumor growth or survival; therefore, our results provide valuable information for the understanding the downstream signal transduction process of the CXCL12–CXCR4–Gαi tricomplex, which could prove useful in the development of anticancer and antimetastatic drugs. The gene discussed is CXCR4; the disease is neoplasm.