Glioma cells release chemo-attractans, such as monocyte chemo-attractant protein-1 (MCP-1), fractalkine (CX3CL1), glial cell–derived neurotrophic factor (GDNF), and colony stimulating factor-1 (CSF)-1) that recruit GAMs to tumor tissue [67]. This evidence concerns the gene CX3CL1 and central nervous system cancer.