In an in vivo murine model of lung cancer and mesothelioma, TGF-β has been reported to promote the tumor supporting functions of neutrophils and treatment with a systemic inhibitor of TGF-β RI led to increased neutrophil recruitment to tumors indicating a negative regulation of neutrophil migration by TGF-β signaling (8). This evidence concerns the gene TGFB1 and mesothelioma.