The product of this gene was shown to confer resistance to a variety of drugs, including taxanes, nucleoside analogs, epothilone B, Vinca alkaloids, anthracyclines, but also to gefitinib, which acts as an epidermal growth factor receptor tyrosine kinase inhibitor (EGFR-TKI) that is often considered clinically as first-line therapy in patients with advanced non-small cell lung cancer (NSCLC) with EGFR-activating mutations [34,35]. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.