CDK9 and cancer: For instance, cancer cells addicted to continuous protein production are particularly vulnerable to CDK9 inhibition.177 On the other hand, CDK9 inhibition represents a potential therapeutic strategy against chemotherapy-persistent tumor cells for its ability to interfere with diapause-like adaptation, necessary for persistent cells to survive the pressure of chemotherapy.712 However, careful dosing and treatment schedules are needed to manage toxicities and optimize therapeutic windows.