This result is in agreement with previous reports showing that although KRAS mutation is a general negative prognostic factor, lung cancer patient response to erlotinib is independent of KRAS status.41, 42 Erlotinib dose used in vitro belongs to the higher ranges of drug concentrations used in other studies with EGFR-mutated cell lines that may display higher responsiveness to EGFR inhibition, particularly at lower doses. This evidence concerns the gene KRAS and lung carcinoma.