The majority of activating EGFR mutations are located in exons 19 (45%) and 21 (40–45%).[14], [15], [16], [17], [18], [19], [20] Guidelines from organizations such as ASCO, CAP/AMP, and NCCN recommend the use of anti-EGFR TKIs as first-line therapy in patients with EGFR-mutant advanced NSCLC based on the results of these pivotal clinical trials. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.