KRAS and lung adenocarcinoma: Consistent with these findings, many studies have reported that TTF‐1 has a strong relationship with EGFR‐mutant lung adenocarcinoma and that TTF‐1 is an oncogene in lung adenocarcinomas with EGFR mutation.33, 34 Shanzhi et al found that the levels of TTF‐1 expression may guide clinical therapy for LUAD with EGFR mutations.35 Moreover, in a previous study, lung adenocarcinoma with KRAS mutation has been found to depend on TTF‐1 expression for growth and to possibly be regulated by survivin protein.36 More studies are needed to elucidate the role of TTF‐1 in the process of PMA.