What is the role of tumor-suppressor genes in the body?

Tumor-suppressor genes play a crucial protective role in the body by preventing uncontrolled cell division. These genes produce proteins that help regulate the cell cycle and ensure that cells do not divide excessively or inappropriately. When functioning properly, tumor-suppressor genes act as a safeguard against cancer by monitoring and repairing DNA damage, promoting apoptosis (programmed cell death) in damaged cells, and regulating other genes involved in the cell division process.

When tumor-suppressor genes are mutated or inactivated, cells can begin to divide unchecked, leading to the development of tumors. This makes their role indispensable in maintaining normal cellular function and in preventing the progression of cancer. The other choices describe functions that are not attributed to tumor-suppressor genes. For instance, promoting rapid cell division and encouraging cell mutation can lead to tumorigenesis, while the initiation of the immune response is primarily the function of immune system-related genes, not tumor-suppressor genes.