While there was no statistically significant difference in terms of mPFS, mOS, and ORR in patients with NSCLC who received first- vs. later-line EGFR-TKI treatment, regardless of EGFR mutation type, patients with EGFR-positive NSCLC characterized by L858R mutation had a significantly longer mPFS if they received EGFR-TKI as the first-line treatment (12.6 vs. 6.3 months, P=0.03). The gene discussed is EGFR; the disease is non-small cell lung carcinoma.