EGFR and lung adenocarcinoma: In lung adenocarcinoma, actionable mutations in the epidermal growth factor receptor (EGFR) occur with a 10–15% frequency and can be effectively targeted with small molecule first- and second-generation tyrosine kinase inhibitors (TKI) (e.g., erlotinib, gefitinib, and afatinib) and monoclonal antibodies (mAbs) (e.g., cetuximab).