Currently, epidermal growth factor receptor (EGFR) tyrosine kinase inhibitors (TKIs), including gefitinib, erlotinib and afatinib, are highly effective in treating lung cancer patients with specific EGFR mutations in their tumor samples, such as exon 19 deletion or exon 21 L858R mutation [21–23]. The gene discussed is EGFR; the disease is neoplasm.