University of Central Florida (UCF) Pathophysiology Exam 1 Practice

An oncogene is a proto-oncogene that has become mutated and overactive, driving uncontrolled cell growth. A normal proto-oncogene helps regulate cell division, but a mutation or overexpression can lock its protein in an active state, sending persistent growth signals that promote proliferation and survival. This contrasts with genes involved in DNA repair, which are typically tumor suppressors; when these are defective, genome instability increases cancer risk, but they don’t act as oncogenes. So the best description is a proto-oncogene that has become mutated and overactive.