What is the primary function of tumor suppressor genes?

Tumor suppressor genes play a crucial role in maintaining cellular integrity by regulating cell division and facilitating the repair of DNA damage. Their primary function is to act as a brake on cell growth and division, preventing cells from proliferating uncontrollably. When these genes are functioning normally, they help ensure that cells do not enter the cell cycle inappropriately and that any DNA damage is repaired before the cell can replicate. This regulatory function is essential for preventing the development of tumors, as mutations or inactivation of tumor suppressor genes can lead to unregulated cell division and ultimately cancer.

The other options describe functions that do not align with the role of tumor suppressor genes. Promoting uncontrolled cell growth is typically associated with oncogenes rather than tumor suppressor genes. Inducing apoptosis can be a feature of some tumor suppressor genes, but it’s not their primary function. Enhancing angiogenesis is typically related to processes that facilitate tumor growth, which is contrary to what tumor suppressor genes do. Therefore, the primary function of tumor suppressor genes, particularly in the context of cancer prevention, is to repair DNA damage and regulate cell division effectively.