Because TGF-β1 inhibition also partially rescued gefitinib sensitivity in the HCC827 GR cells, these data imply a role of TGF-β1 as a potential target in selected EGFR-TKI-resistant NSCLC cells with elevated levels of expression and secretion of TGF-β1. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.