How can mutations in tumor suppressor genes lead to cancer?

Mutations in tumor suppressor genes lead to cancer primarily by allowing uncontrolled cell division. Tumor suppressor genes are responsible for regulating cell growth and ensuring that cells follow the normal process of division and death. When these genes are functioning correctly, they help to control the cell cycle and prevent excessive cell proliferation.

However, when mutations occur in these genes, their ability to suppress abnormal cell growth is compromised. This can result in a loss of control over the cell cycle, allowing cells to divide uncontrollably. As a consequence, abnormal cells may accumulate, leading to the development of tumors and ultimately cancer.

In contrast to the correct answer, options that suggest promoting active cell repair, preventing cells from dividing, or enhancing the immune response do not accurately describe the role of tumor suppressor genes in the context of cancer. Instead of suppressing cell division or enhancing cellular repair mechanisms, mutated tumor suppressor genes contribute to the progression of cancer by failing to inhibit excessive cellular proliferation.