EGFR and cancer: This high incidence of EGFR-related cancers and its association with poor clinical outcomes pave way for development of therapeutic interventions, including small-molecule tyrosine kinase inhibitors (TKIs), including the first-generation gefitinib, erlotinib and icotinib, the second-generation afatinib and dacomitinib and the third-generation osimertinib [14, 15]. The first generation TKIs are typically used to treat patients with high EGFR expression who carry L858R or exon 19 deletion mutations but were resisted by a second mutation T790M.