TGFB1 and neoplasm: In our present study, SB-431542 resulted in regression of the lung metastasis but did not alter growth of primary tumor in the 4T1 model, whereas a monoclonal antibody that neutralizes the three TGF-β ligands decreased both primary tumor growth and lung metastases in the same model, though the effect on metastases was less profound than was seen here with SB-431542 [14].