EGFR and lung adenocarcinoma: In our recently published data, among 814 patients with lung adenocarcinoma, EGFR gene alteration was observed in 503 (61.8%) patients, and the EGFR gene alteration was frequently found in papillary adenocarcinoma (79.8%), acinar adenocarcinoma (72.4%), and lepidic adenocarcinoma (55.3%) [33].