Lung cancer is a terrible disease. In the past, only chemotherapy was available, and even after exhausting chemotherapy regimens, patients suffered from chemotherapy, resulting in a 2-year survival rate of only about 30%, which has been languishing. It was not until the emergence of targeted drugs that the treatment of lung cancer was really improved and the survival time of patients was greatly improved. It is a milestone drug. So what kind of patients are suitable to use it? First of all, only patients with non-small cell type of lung cancer will have the opportunity to use it. For advanced non-small cell lung cancer who have not undergone chemotherapy, genetic testing of tumor tissue is required to use targeted drugs, and only those with genetic mutations can be used; for advanced non-small cell lung cancer who have undergone chemotherapy, targeted drugs can be used directly if the disease has progressed; for advanced non-small cell lung cancer who have undergone chemotherapy, targeted drugs can also be used if the disease has stabilized. For advanced non-small cell lung cancer who have undergone chemotherapy, targeted drugs can be used for maintenance treatment.