Over the last decade, first-generation epidermal growth factor receptor-tyrosine kinase inhibitors (EGFR-TKIs) have been the first treatment choice for NSCLC patients who harbored TKI-sensitive EGFR mutations such as L858R (an amino acid substitution at codon 858 in exon 21), and ex19del (an in-frame deletion in exon19) [2–5]. The gene discussed is EGFR; the disease is non-small cell lung carcinoma.