For example, gefitinib and afatinib, epidermal growth factor receptor tyrosine kinase inhibitors (EGFR-TKIs) that have been developed as targeted therapies for use in patients with non-small cell lung cancer (NSCLC) who have EGFR-activating mutations, significantly improve survival rates in this patient population [16,17,18]. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.