EGFR and lung cancer: Epidermal growth factor receptor (EGFR) is reported as an important driver oncogene in non–small-cell lung cancer (NSCLC) and patients with EGFR mutations, including exon 19 deletion and exon 21 L858R point mutation, initially respond well to the first- or second-generation of EGFR tyrosine kinase inhibitors (EGFR-TKIs) [1].