NCI Dictionary of Cancer Terms
The NCI Dictionary of Cancer Terms features 7,863 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 (PAH-lee-MOR-fih-zum)
A common change in the genetic code in DNA. Polymorphisms can have a harmful effect, a good effect, or no effect. Some polymorphisms have been shown to increase the risk of certain types of cancer.