CTLA4 and neoplasm: In recent years, with the rapid development of tumor immunity research, immune checkpoint inhibitors such as CTLA-4 antibody and PD-1/PD-L1 antibody have been successfully applied in a variety of cancers, such as melanoma, non-small cell lung cancer, advanced cervical cancer, hepatocellular carcinoma, skin squamous cell carcinoma, bladder cancer, etc. Immunotherapy has become one of the main treatment options for patients with advanced cancer.