EGFR and lung adenocarcinoma: Among the therapeutic relevant mutations, EGFR mutations account for approximately 50% of lung adenocarcinoma cases in East Asia [2], and EGFR-tyrosine kinase inhibitors (TKIs) such as gefitinib, erlotinib, and afatinib have been used as molecular-targeted therapeutic agents for patients with EGFR mutation-positive lung adenocarcinoma.