NCI Dictionary of Cancer Terms
The NCI Dictionary of Cancer Terms features 8,234 terms related to cancer and medicine.
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- listen (AN-tee-proh-JES-tin)
- A substance that prevents cells from making or using progesterone (a hormone that plays a role in the menstrual cycle and pregnancy). Antiprogestins may stop some cancer cells from growing and they are being studied in the treatment of breast cancer. An antiprogestin is a type of hormone antagonist.