CXCR4 and neoplasm: The median tumour/kidney ratio was 29.6 (range, 2.3–85.2) for CXCR4, and 0.36 (range, 0.1–2.3) for CXCL12α, respectively, displaying a significant upregulation of CXCR4 in malignant kidney tissue, while its ligand CXCL12α was significantly lower expressed as compared to the corresponding normal renal tissue.