Osimertinib, a third-generation irreversible EGFR tyrosine kinase inhibitor (TKI), targets both EGFR-sensitive mutations (such as exon 19 deletions and L858R mutations) and EGFR T790M mutations, as the preferred treatment choice for EGFR-mutant NSCLC [3, 4]. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.