Treg cells, as one of the most discussed regulatory/immunosuppressive populations within TME, can inhibit the proliferation and activity of tumor-specific Th cells and CTL and NK cells by secretion of transforming growth factor-β (TGF-β), or immunosuppressive cytokines IL-10 and IL-35 and by surface expression of IL-2 receptor subunit α (CD25) (60). This evidence concerns the gene TGFB1 and neoplasm.