CXCR4+ tumorsphere cells potentiated metastatic lung nodules in vivo via SDF-1/CXCR4 signaling, giving a 500% increase relative to controls.<h4>Conclusion</h4>A metastatic CSC subpopulation present in NPC express CXCR4 and have activated EMT and SDF-1/CXCR4-driven metastasis. The gene discussed is CXCL12; the disease is nasopharyngeal carcinoma.