The Hui lab will dissect the mechanism by which the immune system can be exploited to eradicate cancers. Some tumor cells evade immune detection by binding to PD-1—a receptor that keeps immune cells switched off; drugs that block PD-1 have recently shown promise in treating these cancers. As a postdoctoral fellow, I discovered that PD-1 suppresses immune cell activity by blocking the activation of a stimulatory receptor called CD28. Now, our lab will determine whether and how additional immune “checkpoints” operate in conjunction with PD-1 to block CD28 or other immune receptors, and we will identify the inhibitory molecules these systems recruit to dampen the immune response. Our findings could lead to the development of novel immunotherapeutic agents and could hold the key to treating patients who develop a resistance to inhibitors of PD-1.