Epidermal growth factor receptor (EGFR) is expressed on the cell surface, with activating EGFR mutations commonly observed in patients with adenocarcinomas with no prior history of smoking, as well as in females and those of Asian descent, with targeted therapies including gefitinib, erlotinib, afatinib, dacomitinib, and osimertinib (all TKIs). The gene discussed is EGFR; the disease is adenocarcinoma.