Osimertinib is effective against EGFR mutation, especially the EGFR T790M mutation,1 and is recommended as the first‐line therapy for EGFR‐mutated NSCLC2 and also recommended as adjuvant therapy for completely resected stage II–IIIA EGFR‐mutated NSCLC.3 This evidence concerns the gene EGFR and non-small cell lung carcinoma.