PD-1 (Programmed Death-1)

PD-1 (Programmed Death-1) is a protein found on immune cells called T-cells, which help the body fight infections and cancer. When PD-1 binds to its partners (PD-L1 or PD-L2), it acts as a brake, reducing the T-cell’s activity to prevent overreaction and protect healthy tissues. However, some cancer cells exploit this mechanism by producing PD-L1, effectively turning off T-cells and avoiding immune attack. Drugs called PD-1 inhibitors block this interaction, reactivating the immune cells to recognize and destroy cancer cells more effectively.