What Role Do Oncogenes and Tumor Suppressor Genes Play in Prophase?
Oncogenes and [tumor suppressor genes]() play crucial roles in regulating the cell cycle. Oncogenes like [Cyclin D1]() and [CDK4]() drive the cell cycle forward, including the transition from G1 to [S phase]() and subsequently into mitosis. Overactivation of these genes can lead to premature and uncontrolled entry into prophase. Conversely, tumor suppressor genes like p53 and [RB1]() act as brakes, ensuring that cells do not enter prophase with damaged DNA. Mutations that inactivate these tumor suppressors remove these critical checkpoints, allowing cancer cells to divide unchecked.
