CXCL12 and cancer: It is well-known that the macrophages contribute significantly to pathogen eliminating and cancer killing at early-stage of the disease [77], while the tumor cells released several chemokines (CCL2, CCL5 and CXCL12) and cytokines (VEGF and Csf1) to recruit more monocytes that are primitive macrophage M0 and they promote differentiation to macrophages M2 at advanced tumor-stages [78].