TGFB1 and neoplasm: Based on the beneficial effect on survival and tumor regression observed in preclinical studies, we conducted a phase I/II randomized clinical trial to test in advanced, metastatic breast cancer patients the feasibility and efficacy of combining TGFβ blockade by fresolimumab (GC1008), a human IgG4 kappa monoclonal antibody that neutralizes all mammalian isoforms of TGFβ [10], and radiotherapy.