EGFR and non-small cell lung carcinoma: Our findings shed light on the clinical efficacy of different first-line EGFR-TKIs in advanced EGFR-mutant NSCLC patients, the clinical efficacy of sequential osimertinib therapy in patients with T790M-positive after acquired resistance to first-line EGFR-TKI, as well as the impact of different first-line EGFR-TKI use to the clinical outcomes of subsequent osimertinib treatment.