NCI Dictionary of Cancer Terms
The NCI Dictionary of Cancer Terms features 7,846 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 (OH-ver-ek-SPRES)
- In biology, to make too many copies of a protein or other substance. Overexpression of certain proteins or other substances may play a role in cancer development.