In recent years, osimertinib has emerged as a third-generation EGFR-TKIs that can active and target both sensitive and resistant (T790M) EGFR mutations.46 In the FLAURA study, the median PFS of NSCLC patients treated with osimertinib (18.9 months) was obviously longer than that in patients treated with first-generation EGFR-TKIs (gefitinib and erlotinib) (10.2 months).47 This group of patients had EGFR exon 19 deletions or L858R mutations in untreated NSCLC that had progressed. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.