A study by Segawa et al. [51] demonstrated that high levels of CXCR4 and VEGF correlate with a poor prognosis in NPC patients, and Bachelder et al. [52] demonstrated that VEGF promotes breast cancer tumor cell invasion via the upregulation of CXCR4 expression. The gene discussed is CXCR4; the disease is nasopharyngeal carcinoma.