CXCR4 and neoplasm: Although few studies have addressed the significance of chemokine/chemokine receptor expression in NSCLC, it has been suggested that, for NSCLC, higher expressions of CXCR1, CXCR2, and CXCR4 with their ligands CXCL5, CXCL8, and CXCL12 are associated with tumor angiogenesis, metastasis, and poor survival [2-4,11,13-17].