CXCL12 and neoplasm: Starting from this evidence, Brown and colleagues [109] speculated that tumor recurrence could be markedly reduced by inhibition of the circulating pro-angiogenic CD11b+ myelomonocytes that express high levels of stromal cell-derived factor 1 (SDF1) playing a key role in angiogenesis by recruiting endothelial progenitor cells through a CXCR4/CXCR7 dependent mechanism.