G0 phase

The G₀ phase (called the G zero phase) or resting phase is a period in the cell cycle in which cells are inactive. Cells enter G₀ phase from G₁ and stop dividing. Some cells, such as neurons, remain in G₀ for indefinite period. Some cells enter G₀ phase semi-permanently, such as some cells of the liver and kidney. Many cells do not enter G₀ and continue to divide throughout an organism's life, e.g. epithelial cells.