Tumor suppressor genes are essential components of the body's regulatory system that help prevent uncontrolled cell growth. They produce proteins that repair DNA, regulate the cell cycle, and promote apoptosis, which is the process of programmed cell death. When these genes are functioning properly, they act as a safeguard against the development of tumors. However, mutations or deletions in tumor suppressor genes can lead to a loss of their protective functions. This can result in the unchecked proliferation of cells, contributing to the formation of cancers. A well-known example of a tumor suppressor gene is TP53, which plays a critical role in maintaining genomic stability.