EGFR tyrosine kinase inhibitors (EGFR-TKIs) have recently shown efficacies toward NSCLC, including gefitinib and erlotinib, which have been widely used to treat NSCLC with in-frame deletions of exon 19 and exon 21 L858R point activating mutation. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.