CXCL12 and colonic neoplasm: Upregulation of CXCR4 in radioresistant colon cancer endothelial cells is strongly associated with recruitment of stromal cell-derived factor 1 (SDF-1, also known as CXCL12)+TAMs and their polarization toward an M2 phenotype; this can be reversed by administration of the CXCR4 antagonist AMD3100 (64).