EGFR and lung cancer: Non-small cell lung cancer (NSCLC) represents 80% of lung cancers, and it is estimated that 15% of all NSCLC (especially younger patients with adenocarcinoma histology or a limited smoking history) [2] carry an EGFR-activating mutation [3] that increases the responsiveness to EGFR tyrosine kinase inhibitors (TKIs) such as erlotinib, gefitinib, or afatinib [4].