The cell cycle is the sequence of events through which a cell duplicates its genome, grows, and divides into two daughter cells. It encompasses one of the most fundamental properties of life. The cell cycle is divided into four phases. After cell division, daughter cells undergo a period of growth (G1) when cellular macromolecules including proteins, RNA, and membranes are synthesized. G1 is followed by a period of DNA synthesis (S). After another period of growth (G2), cells undergo mitosis (M), during which the DNA is divided equally into two daughter cells, cumulating in cytokinesis. Most nondividing cells exit the cell cycle at G1 into quiescence (G0).