TGFB1 and glioma: There is communication between glioma cells and macrophages through TGF-β: glioma cells secrete TGF-β that participates in M2 polarization by macrophages [155]; in turn, macrophages secrete this immunosuppressive cytokine, leading to immune surveillance suppression and promotion of tumor angiogenesis, invasion, and metastasis [156].