TGFB1 and lung adenocarcinoma: The contextual responses leading to the dual role of TGF-β signaling in breast, colorectal, pancreatic, liver and lung adenocarcinoma is exemplified by the cell growth arrest and induction of cell death mediated by apoptosis in early-stage epithelial tumors, while the cancer cells that escape TGF-β suppression respond to TGF-β with tumorigenic immunosuppression, invasion and metastasis, thus promoting tumor progression [8].