The human anti-TGFβ monoclonal antibody (GC1008) that neutralizes all isoforms of TGFβ was tested in a phase I clinical trial in patients with advanced malignant melanoma or renal cell carcinoma (NCT00356460), and the antibody showed antitumor efficacy with no dose-limiting toxicity at a dose of up to 15 mg/kg, with acceptable safety. This evidence concerns the gene TGFB1 and renal cell carcinoma.