Based on The Cancer Genome Atlas data of 456 primary lung adenocarcinomas (mostly Caucasian cases), the frequency of KRAS mutations was not significantly higher in HNF4A-high cases (35.9%, 42/117 cases) than in HNF4A-low cases (29.5%, 100/339 cases) (p = 0.121) (Online resource 9). This evidence concerns the gene HNF4A and lung adenocarcinoma.