For stage IIIB or IV HER2-mutant lung adenocarcinoma patients who have previously received platinum chemotherapy, the objective effective rate (ORR) of pyrotinib therapy is 30.0% (95%CI 18.8%-43.2%), the mPFS is 6.9 months (95%CI 5.5-8.3), and the mOS is 14.4 months (95%CI 12.3- 21.3) (19). The gene discussed is ERBB2; the disease is lung adenocarcinoma.