In summary, recruitment and subsequent M2 polarization of GAMs has been shown to be mediated by multiple glioma cell-derived chemoattractants such as MCP-1 (CCL2), SDF-1 (CXCL12), M-CSF (CSF-1), GM-CSF, and EGF (Figure 3). This evidence concerns the gene CXCL12 and glioma.