What is the function of a tumor-suppressor gene?

A tumor-suppressor gene plays a critical role in regulating cell growth and division, primarily by inhibiting processes that could lead to cancerous behavior in normal cells. Tumor-suppressor genes produce proteins that help maintain normal cell cycle progression, repair damaged DNA, and promote cellular functions that prevent the uncontrolled proliferation of cells.

When these genes are functioning properly, they can detect and respond to abnormalities such as DNA damage or inappropriate cell signaling, thereby providing a safeguard against the development of tumors. On the other hand, mutations or deletions in these genes can lead to a loss of function, resulting in a failure to control cell growth and division, which may ultimately contribute to the development of cancer.

While some tumor-suppressor genes also play roles in DNA repair and apoptosis, their overarching function is to inhibit the cancerous behavior of normal cells, making this the most accurate description of their role.