Standard systemic treatment for patients with stage IIB/IV NSCLC with sensitizing epidermal growth factor receptor (EGFR) mutation includes either first-generation EGFR-tyrosine kinase inhibitor (TKI) (gefitinib or erlotinib) or second-generation TKI (afatinib). The gene discussed is EGFR; the disease is non-small cell lung carcinoma.