EGFR and non-small cell lung carcinoma: Mutations in the epidermal growth factor receptor (EGFR) are recognized as promising biomarkers for therapies using tyrosine kinase inhibitors (TKIs) as treatments for non-small-cell lung cancer (NSCLC).1, 2, 3 Resistance to TKIs frequently occurs in EGFR-mutated NSCLC patients who have undergone TKI treatment and this resistance is considered to represent an acquired (secondary) resistance.4, 5