Thus in our study, the analysis of the TTF-1 expression and EGFR mutations shows TTF-1 positive expression and EGFR mutations each has correlation with sex(p = 0.045;p<0.001),smoking(p = 0.007;p<0.001) in lung adenocarcinomas, especially for those female and nonsmokers, which have significant TTF-1 positive expression(Female:292/294,99.31%, Male:362/370,97.83%;No amoking :436/439,99.31%,Smoking:218/225,96.89%) and EGFR mutation(Female: 145/294,49.32%,Male: 117/370,31.62%;No smoking:203/439,46.24%;Smoking:59/225,26.22%). Here, EGFR is linked to lung adenocarcinoma.