A 62-year-old non-smoking woman with advanced lung adenocarcinoma who responded with stable disease (SD) to sequential treatments with Icotinib and Osimertinib, the PFS with Osimertinib treatment is much longer than that with Icotinib (19 months vs 8.2 months) and the OS is more than 3 years.[13] Besides, an in vitro study has showed that despite displaying resistance to first-generation reversible EGFR-TKIs, L858R/D761Y mutant cells were sensitive to irreversible inhibitors, especially the third-generation EGFR-TKIs.[14]. The gene discussed is EGFR; the disease is lung adenocarcinoma.