TGFB1 and neoplasm: TGF-β reduces the cytotoxic function of NK cells and CTLs36 and induces the conversion of NK cells into type 1 innate lymphoid cells in the TME, which fail to control tumor growth and metastasis.37 TGF-β signaling also drives the trans-differentiation of Th17 cells into Tregs, resulting in the development of immune tolerance and immunosuppression in the TME.38 TGF-β can be produced by both immune and non-immune cells.