The results of these phase III trials led to the approval of EGFR TKIs for first-line therapy of patients with advanced EGFR mutation-positive NSCLC and to clinical practice guidelines recommending, first, EGFR mutation testing for all patients with advanced adenocarcinomas, and, second, EGFR TKIs as the preferred first-line therapy for patients with advanced EGFR mutation-positive NSCLC [24–27]. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.