Moreover, evidence indicates that CXCL12 [also known as stromal-derived factor-1 (SDF-1)] can also promote angiogenesis by stimulating CXCR4-positive cancer cells to secrete VEGF and IL-6 [19], and that this chemokine contributes to the ability of tumor cells to evade immune surveillance by regulating the trafficking of immune cells [20]. Here, CXCL12 is linked to cancer.