Oncogene

**Semantic type:** Gene or Genome

**Definition:** A gene that normally directs cell growth. If mutated or overexpressed in a dominant fashion, it can release the cell from normal restraints on growth. It alone or in concert with other changes, converts the cell into a tumor cell. Alterations can be inherited or caused by an environmental exposure to carcinogens.

**Synonyms:** - Cancer-Promoting Gene - oncogene