First-generation EGFR tyrosine kinase inhibitors (TKIs) such as gefitinib and erlotinib that possess a 4-anilinoquinazoline scaffold, reversibly inhibit EGFR mutants (L858R and delE746_A750) as well as wild-type (WT) EGFR, resulting in significant disease control of patients with NSCLC (Figure 1) (Cohen et al., 2005; Cheng et al., 2016). The gene discussed is EGFR; the disease is non-small cell lung carcinoma.