NCI Dictionary of Cancer Terms
The NCI Dictionary of Cancer Terms features 7,777 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.
- opportunistic infection
- listen (AH-per-too-NIS-tik in-FEK-shun)
- An infection caused by an organism that does not normally cause disease. Opportunistic infections occur in people with weakened immune systems.