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. Here, CTLA4 is linked to cancer.