PD-L1 (Programmed Cell Death Ligand 1)

PD-L1 (Programmed Cell Death Ligand 1) is a protein found on the surface of some cells, including certain cancer cells. It plays a role in regulating the immune system by binding to the PD-1 receptor on immune cells, which sends an "off" signal. This helps normal cells avoid immune attack, but cancer cells can exploit this to avoid being destroyed. In cancer treatment, blocking PD-L1 or PD-1 can help restore the immune system's ability to recognize and attack tumors, forming the basis for certain immunotherapies.