The cell cycle is composed of S (synthetic) phase and M (Mitotic) phase. In between are G1
and G2 phases. cyclin-dependent kinases propel cell division. Their activation
results in the progression of a cell from one
phase to another while their inactivation
arrests a cell in a phase. In case of
damage to DNA during a cell cycle, transcription factors p53 (a renowned tumor suppressor) are recruited. P53 inhibits
cyclins-dependent kinases and also
induces cell apoptosis if DNA is not repaired.