Oncology Certified Nurse (OCN) Nursing Practice Test

Which of the following best describes the role of tumor suppressor genes?

1. Promoting cell division

2. Inhibiting uncontrolled cell growth

3. None of the above

4. Causing mutations in cells

The correct answer is: Inhibiting uncontrolled cell growth

Tumor suppressor genes play a critical role in regulating cell growth and maintaining genomic stability. Their primary function is to inhibit uncontrolled cell division, which is essential in preventing the formation and progression of tumors. By producing proteins that counteract cell growth and division signals, tumor suppressor genes help to ensure that cells divide in a controlled manner. When these genes are mutated or inactivated, the regulatory effect is lost, leading to unregulated cell proliferation and potentially resulting in cancer development. In contrast, promoting cell division is more characteristic of oncogenes, and causing mutations in cells does not accurately describe the protective role of tumor suppressor genes; instead, mutations can occur in any gene and contribute to cancer risk. Therefore, the correct choice indicates the fundamental protective mechanism of tumor suppressor genes against cancer.