NCI Dictionary of Cancer Terms
The NCI Dictionary of Cancer Terms features 7,894 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 (ON-koh-jeen)
- A gene that is a mutated (changed) form of a gene involved in normal cell growth. Oncogenes may cause the growth of cancer cells. Mutations in genes that become oncogenes can be inherited or caused by being exposed to substances in the environment that cause cancer.