What is the function of tumor suppressor genes?

Tumor suppressor genes play a crucial role in regulating cell growth and division, acting as a safeguard against uncontrolled cellular proliferation that can lead to tumor formation. Their primary function is to inhibit cell division and promote apoptosis, the process of programmed cell death. This regulation is essential because when tumor suppressor genes are functioning correctly, they help maintain normal cellular homeostasis by preventing cells from dividing too quickly or inappropriately.

When these genes are mutated or inactivated, the normal checks on cell growth are lost, which can lead to the development of cancers. In this way, tumor suppressor genes serve as a critical line of defense against cancer by ensuring that damaged cells either repair themselves or undergo apoptosis, thereby preventing potential malignancies.

The other choices do not accurately describe the primary role of tumor suppressor genes. For instance, promoting cell division and survival are functions associated with oncogenes, while suppressing the immune response is not relevant to the function of tumor suppressor genes. Enhancing cellular repair processes may occur as a consequence of normal cellular function but is not the main function of these genes.