Microglia and macrophages are vigorously triggered by the glioma via the expression of chemoattractants such as monocyte chemoattractant protein (MCP-1, also known as CCL2), stromal-derived factor-1 (SDF-1), and macrophage-colony stimulating factor (M-CSF) [7, 8]. Here, CCL2 is linked to glioma.