TTF1 and lung cancer: Therefore, successive research work on both the potential effect of TTF-1-promoter-operating miR-7 expression on other types of cancers and regulatory factors including transcript factors in the activation of TTF-1 promoter, which did not been investigated in present study, is valuable for the verification of usage of the TTF-1 promoter in targeted gene expression in lung cancer and can ultimately benefit the development of a therapeutic strategy in clinical lung cancer.