Besides, among molecular subtypes of lung adenocarcinoma, significant decrease of FSTL1 expression in KRAS mutation or ALK mutation tumor shown in our study also suggests that FSTL1 has variable influence on different molecular subtypes of lung adenocarcinoma and points out the direction of FSTL1 as a target for personalized therapeutic approach. This evidence concerns the gene KRAS and lung adenocarcinoma.