In summary, in our xenograft mouse models, the anti-metastatic properties of TGF-β signaling antagonists appear to be mediated both by tumor cell autonomous effects and by modulating tumor:host interactions via several different mechanisms, including inhibition of angiogenesis in the case of lung metastases and inhibition of osteoclast activity in the case of bone metastases. This evidence concerns the gene TGFB1 and neoplasm.