Several randomized clinical trials have shown that first‐generation EGFR tyrosine kinase inhibitors (TKIs), including gefitinib and erlotinib, and second‐generation EGFR‐TKIs, including afatinib, achieved a good clinical response in lung cancers harboring activating EGFR mutations (Maemondo et al., 2010; Yang et al., 2015; Zhou et al., 2011). Here, EGFR is linked to lung cancer.