For epidermal growth factor (EGFR)-mutated non-small cell lung cancer (NSCLC), osimertinib is an oral, third-generation EGFR tyrosine kinase inhibitor (EGFR-TKI) that selectively inhibits EGFR mutations and T790M resistance mutations, and is the first-line systemic therapy for advanced disease and as adjuvant therapy in patients with resected disease (2, 9, 10). The gene discussed is EGFR; the disease is non-small cell lung carcinoma.