NCI Dictionary of Cancer Terms
The NCI Dictionary of Cancer Terms features 7,926 terms related to cancer and medicine.
Browse the dictionary by selecting a letter of the alphabet or by entering a cancer-related word or phrase in the search box.
- listen (pep-SIH-noh-jen)
- A substance made by cells in the stomach. Acid in the stomach changes pepsinogen to pepsin, which breaks down proteins in food during digestion.