Furthermore, excessive production of tumor-derived TGF-β could suppress T-lymphocytes and natural killer cells, leading to cellular escape of cancer cells from cytotoxic T lymphocyte clearance.507 Target blockade of TGF-β signaling in T-cells results in eradication of tumors in mice challenged with live tumor cells,508 indicating the suppressive action of TGF-β signaling on the T-cell mediated antitumor immunity. This evidence concerns the gene TGFB1 and cancer.