EGFR and non-small cell lung carcinoma: Activating mutations in exons 19 or 21 of the tyrosine kinase domain of the epidermal growth factor receptor (EGFR) gene are present in 12–40% of non-small cell lung cancer (NSCLC) tumors and have been demonstrated to predict clinical response to first- and second-line EGFR tyrosine kinase inhibitors (TKIs) with differentiated outcomes (response rates, progression-free survival, and quality of life) compared to standard chemotherapy [6,7,8,9,10,11,12,13,14].