In addition, as reported by our group and other investigators, SDF-1 is one of the potent chemo attractants for bone marrow derived endothelial progenitor cells due to the presence of CXCR4 receptors in these cells [27], [38], and it may be involved in enhanced angiogenesis and invasiveness of the tumor following treatment with VEGFRs inhibitors. This evidence concerns the gene CXCL12 and neoplasm.