In the 256 nodules of all patients, EGFR mutation was frequently detected in tumors located in the upper portion of the lung (79/113 cases, or 69.9%) and adenocarcinoma was common (111/113 cases, or 98.2%), especially in tumors with acinar-predominant pattern (85/113 cases, or 76.6%), which is similar to other studies (41, 43, 44). The gene discussed is EGFR; the disease is adenocarcinoma.