M2-like TAMs contribute to the immunosuppressive TME by secreting immunosuppressive factors such as IL-6, TGF-β, IL-10 in GBM, while only low levels of M1-like pro-inflammatory cytokines such as IL-2, IL-12, TNF-α and IFN-γ are detected (52, 71, 72). Here, TGFB1 is linked to glioblastoma.