Two patients showed EGFR A763_Y764insFQEA, which has been considered as sensitive to classical EGFR tyrosine kinase inhibitors (EGFR-TKIs). Two patients (EGFR A763_Y764insFQEA and EGFR T751_I759>S) had received erlotinib during their treatment course and both of them showed stable disease with a progression-free survival of 5.9 and 10.1 months, respectively.