Used in the treatment of various cancers, particularly melanoma and other solid tumors, by enhancing the immune system's ability to detect and attack cancer cells. It functions by blocking the CTLA-4 receptor on T-cells, which removes inhibitory signals that dampen immune responses. This leads to increased T-cell activation and proliferation, promoting stronger anti-tumor immunity. Often used in combination with other immunotherapies, such as PD-1 inhibitors, to improve clinical outcomes. Currently investigated in clinical trials for efficacy across different cancer types and in combination regimens.