NCI Dictionary of Cancer Terms
The NCI Dictionary of Cancer Terms features 8,177 terms related to cancer and medicine.
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- immune checkpoint inhibitor
- listen (ih-MYOON CHEK-poynt in-HIH-bih-ter)
A type of drug that blocks certain proteins made by some types of immune system cells, such as T cells, and some cancer cells. These proteins help keep immune responses in check and can keep T cells from killing cancer cells. When these proteins are blocked, the “brakes” on the immune system are released and T cells are able to kill cancer cells better. Examples of checkpoint proteins found on T cells or cancer cells include PD-1/PD-L1 and CTLA-4/B7-1/B7-2. Some immune checkpoint inhibitors are used to treat cancer.