Checkpoint inhibitors work by targeting specific proteins on T cells or cancer cells. The most commonly targeted checkpoint proteins are CTLA-4 (cytotoxic T-lymphocyte-associated protein 4) and PD-1 (programmed death-1), along with its ligand PD-L1 (programmed death-ligand 1). By blocking these proteins, checkpoint inhibitors enable T cells to recognize and destroy cancer cells more effectively.
