It was found that tumor-associated microglia/macrophages upregulate the release of transforming growth factor β (TGF-β), EGF, IL-10, and monocyte chemoattractant protein (MCP1, aka CCL2), leading to increased invasion and proliferation of glioma cells and provide a favorable environment for tumor growth [6,9,13,16,18]. Here, CCL2 is linked to glioma.