Review Volume 3, Issue 2 pp 94—101

Figure 1. Two types of cell cycle arrest. (A) Proliferating cells. Growth stimulation leads to mass growth, which is balanced by cell division. (B) Quiescence. Withdrawal of growth factors deactivates both growth-promoting pathways and the cell cycle. (C) Senescence. The block of the cell cycle, in the face of growth-stimulation, causes condition known as cellular senescence.