In 244 patients with lung adenocarcinoma, the total mutation rate of driver genes was 65.17%, including EGFR 48.36% (118/244), KRAS 6.15% (15/244), ALK 5.74% (14/244), HER-2 2.05% (5/244), ROS1 1.23% (3/244), RET 0.82% (2/244), NRAS 0.41% (1/244), BRAF 0.41% (1/244), PIK3CA 0.00% (0/244), and MET 0.00% (0/244). The gene discussed is PIK3CA; the disease is lung adenocarcinoma.