The cell cycle is a process in which a cell begins with division, passes through a series of orderly life cycle stages, and finally completes one division. Including mitosis (M phase) and interphase (G1, S, G2). In S phase, DNA is synthesized and replicated; in G2 phase, it prepares to enter mitosis; after mitosis is completed, it enters G1 phase. The regulation of the cell cycle is precisely regulated by multiple cell cycle proteins and kinases to ensure the orderly progress of cell division. Studying the cell cycle is of great significance to understanding cell biology, cancer mechanisms and drug treatment.