As a seven-transmembrane G protein-coupled chemokine receptor, CXCR4, which plays a role in cell motility, invasion, and angiogenesis in tumor cells, has also been found to be a prognostic marker in various types of cancer and to be upregulated in cancer metastasis, thereby implying the importance of CXCR4 to the development of tumors (Furusato et al., 2010). This evidence concerns the gene CXCR4 and cancer.