TGFB1 and neoplasm: Moreover, not only are these pro-tumor immune populations induced by TGFβ1, but at least in the case of tumor-associated macrophages (TAM), these cells can become potent producers of TGFβ1 themselves [97,98], thus further contributing to the immunosuppressive and tumor-promoting effects of this cytokine within the tumor microenvironment during cancer progression.