TGFB1 and neoplasm: These can be systemic, such as decreased T-cell responsiveness, increased Tregs, decreased monocyte and dendritic cell function, lower level of immunoglobulins, frequent use of corticosteroids, and lymphopenia caused by treatments, or local, such as downregulation of MHC molecules, secretion of TGF-β, VEGF, PG-E2, IL-10, LLT-1, polarization of microglia and tumor-associated macrophages towards the immunosuppressive M2 phenotype [125], decreased T-cell function due to hypoxia, T-cell apoptosis through Fas, infiltration with Tregs, and increased expression of immune checkpoints [126].