I am investigating the induction of a stable and permanent cell cycle arrest, senescence using cytostatic drugs, more precisely cyclin-dependent kinase (CDK) inhibitors. CDKs are fundamental to the cell cycle regulation and progression. However, different stress stimuli can lead to a cell cycle arrest which can be reversible and irreversible. Because of the known role of CDK inhibitors p21 and p16 in causing cell cycle arrest, there has been a greater interest in pharmacologically inhibiting CDKs as anti-cancer therapies. There are a number of CDK inhibitors in preclinical studies with some already being used in the clinic. The aim of my project is therefore to investigate the permanent exit from the cell cycle by different CDK inhibitors.