Different histologic subtypes vary in pathologic and molecular features, leading to differences in treatment and prognosis. In the adenocarcinoma subtype, five-year progression-free survival in patients with EGFR mutation treated with an EGFR-TKI is 14.6% as compared to less than 5% in unselected patients with distant-stage NSCLC. The gene discussed is EGFR; the disease is adenocarcinoma.