Epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) were permitted as the first-line targeted drugs for the treatment of advanced lung adenocarcinoma with mutated EGFR in the guidelines of the national comprehensive cancer network (NCCN)1 and the European society of medical oncology (ESMO)2 due to its longer progression-free survival than chemotherapy3. This evidence concerns the gene EGFR and cancer.