Transforming growthfactor-β (TGF-β) increases cell-surface CXCR4 protein expression on humanmelanoma cells [35] and we have recently found that FGF-2 upregulates CXCR4 onhuman colorectal cancer cells (Bseso B and Blay J, manuscript in preparation). This evidence concerns the gene CXCR4 and colorectal cancer.