Immune checkpoint inhibitors, illustration - stock photo

Immune checkpoint inhibitors, illustration. Immune checkpoints are regulators of the immune system. Antibodies (light blue and red) block the interaction between PD-L1 (programmed cell death 1 ligand 1, red molecule) on the surface of a cancer cell (large red) and the immune checkpoint PD-1 (programmed cell death protein 1, blue molecule) on a T-cell (large blue), that would lead to the inhibition of T-cell killing tumour cells