TGFB1 and cancer: In this experiment, circulating cancer cells did not grow ex vivo in the presence of the TGF-β antibody and irradiation failed to enhance lung metastases in mice bearing tumors that lacked the type II TGF-β receptor, suggesting that the increase in metastases was due to a direct effect of TGF-β on the cancer cells (Biswas et al., 2007).