Immune checkpoint therapy is a type of cancer treatment that helps the body's immune system recognize and attack cancer cells. It works by blocking proteins, known as immune checkpoints, that normally keep immune responses in check. By inhibiting these proteins, the therapy allows immune cells, like T cells, to become more active against tumors. This approach has shown promise in treating various cancers, including melanoma and lung cancer. Common immune checkpoint inhibitors include nivolumab and pembrolizumab, which target specific checkpoints such as PD-1 and CTLA-4. These therapies can lead to long-lasting responses in some patients, improving survival rates.