KRAS and lung adenocarcinoma: In a previous study, no (0.0% (0/945)) lung adenocarcinoma patients had KRAS mutations with EGFR mutations, while one patient (0.1% (1/897)) had EML4–ALK and EGFR mutations in Asian populations [34], thus the very low proportion (nearly zero) (co-occurrences of driver mutations) almost could not influence the prognosis of patients receiving TKIs in this study.