Used in cancer immunotherapy to treat advanced melanoma by enhancing the immune system’s ability to attack tumor cells. It blocks the CTLA-4 receptor on T-cells, removing inhibitory signals that suppress T-cell activation. This leads to increased T-cell proliferation and anti-tumor activity. Also investigated for use in other cancers such as renal cell carcinoma, non-small cell lung cancer, and colorectal cancer, often in combination with other immunotherapies like anti-PD-1 antibodies. Administered intravenously in clinical settings under medical supervision due to risk of immune-related adverse effects.