EGFR and non-small cell lung carcinoma: The T790M mutation of EGFR has been detected in up to 50% of NSCLC patients who develop resistance to first‐ or second‐generation EGFR‐TKIs.7, 8, 9 Osimertinib is a third‐generation EGFR‐TKI that shows efficacy for T790M‐positive NSCLC and can also be used in clinical practice as a second‐line treatment if the T790M mutation is detected by liquid biopsy in patients for whom tissue rebiopsy is problematic.16 In contrast, an effective targeted drug for T790M‐negative NSCLC resistant to EGFR‐TKIs has not yet been approved.