Osimertinib is a novel mutant-selective irreversible third-generation EGFR TKI, which exhibits minimal effect on wild type EGFR (wtEGFR) and therefore less adverse effects, demonstrating potent anticancer activity in EGFR-mutated (mutEGFR) NSCLC patients harboring the T790M gatekeeper mutation [5]. This evidence concerns the gene EGFR and non-small cell lung carcinoma.