In 2009, a retrospective study of 23 Korean never-smoker patients with lung adenocarcinoma and brain metastasis without prior whole brain radiotherapy (WBRT) found that gefitinib or erlotinib without WBRT resulted in an intracranial response rate of 73.9%, noting that the prevalence of EGFR mutations in Korean non-smoker NSCLC population is high (44). The gene discussed is EGFR; the disease is non-small cell lung carcinoma.