However, their effectiveness varies depending on the number and size of metastatic brain lesions, with whole-brain radiation therapy typically yielding response rates between 50% and 75%, and survival rates ranging from 4 to 9 months Recent advances in tumor immunology research have led to the development of targeted therapies, such as CTLA-4 and PD-1/PD-L1 inhibitors, which have shown promising efficacy rates compared to traditional chemotherapeutic agents (120, 121). The gene discussed is PDCD1; the disease is neoplasm.