Terence Kin-Wah Lee and Nicole Pui-Yu Ho
In recent years, cancer immunotherapy has been a recent hot topic among scientists over the world. So far, the discovered checkpoint protein molecules include cytotoxic T lymphocyte antigen-4 (CTLA-4), programmed death-1 (PD-1), lymphocyte activation gene-3 (LAG-3) and several others. The overexpression of the checkpoint proteins could lead the decreased T-cell cytotoxicity, proliferation and cytokine production.