The immunosuppressive molecules galectin, SPP1, MIF, and complement impede the T cell response. In addition to their immunosuppressive role in the TME, the present study supports the view that TAMs directly facilitate glioma cell proliferation through their secreted ligands, such as galectin and SPP1, along with direct cell-to-cell contact mechanisms. This evidence concerns the gene SPP1 and central nervous system cancer.