Similar to previous findings [23, 25, 26], smokers were more commonly found to have squamous cell carcinoma and KRAS mutation, and less likely to have EGFR L858R mutation in our cohort, and those associations between smoking and histological type, EGFR L858R mutation (but not KRAS mutation) were also observed after standardization of gender. The gene discussed is KRAS; the disease is squamous cell carcinoma.