What is the primary function of tumor suppressor genes in cancer development?

Tumor suppressor genes play a crucial role in regulating cell growth and maintaining genomic stability. The primary function of these genes is to control or modify the activity of oncogenes, which are responsible for promoting cell division and growth. When tumor suppressor genes are functioning properly, they help to inhibit excessive cell proliferation and can trigger mechanisms that halt the cell cycle or initiate programmed cell death (apoptosis) in cells that are damaged or dysfunctional.

In cases where tumor suppressor genes are mutated or inactivated, the regulatory control they exert over oncogenes is lost, leading to unregulated cell division and, potentially, cancer development. This highlights the importance of tumor suppressor genes in maintaining balance within cellular processes, ensuring that cell growth remains under tight control.

While some options suggest interactions with DNA repair or cell division, they do not accurately capture the primary role of tumor suppressor genes as regulators of oncogene activity. This regulation is critical for preventing the transformation of normal cells into cancerous ones.