CXCR4 is a 7-transmembrane G-protein coupled receptor [10] and highly expressed in a variety of cell types, including lymphocytes, endothelial, epithelial and hematopoietic stem cells, stromal fibroblasts and cancer cells [11] and plays a major role in embryogenesis, homeostasis and inflammation [12]. This evidence concerns the gene CXCR4 and cancer.