EGFR and non-small cell lung carcinoma: Approved by the U.S. Food and Drug Administration (FDA) in 2015, gefitinib has been used for the first-line treatment of NSCLC patients with EGFR mutations, and many clinical studies have demonstrated that it prolongs progression-free survival when compared with existing treatment methods (Mok et al., 2009; Kazandjian et al., 2016).