Programmed Cell Death Protein 1

Programmed Cell Death Protein 1 (PD-1) is a receptor found on immune cells called T-cells. Its role is to help regulate the immune system by preventing T-cells from attacking the body's own tissues, thus reducing inflammation and autoimmune responses. When PD-1 binds to its ligands, it sends a signal that dampens the T-cell's activity. This mechanism helps maintain immune balance, but some cancer cells can exploit PD-1 by activating this pathway to avoid immune attack. That's why PD-1 inhibitors, a type of immunotherapy, are used to block this interaction and help the immune system fight cancer more effectively.