We used the following search strategy and keywords: “Epidermal growth factor receptor” OR “EGFR” OR “epidermal growth factor receptor mutation” AND “Carcinoma, Non-Small-Cell Lung” OR “NSCLC” OR “non-small cell lung cancer” OR “lung adenocarcinoma” OR “lung cancer” OR “lung carcinoma” AND “Tomography, X-Ray Computed” OR “Tomography, Spiral Computed” OR computed tomography” OR CT” AND “Biopsy” OR “cytology”. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.