The rate of cell proliferation is determined by a balance between cell division and cell death. Factors influencing this rate include the type of tissue, age of the organism, genetic factors, and external stimuli such as hormones and nutrition. In rapidly renewing tissues like the intestinal epithelium and bone marrow, proliferation rates are high. Conversely, in tissues like the brain, proliferation is much slower. Regulatory mechanisms, such as the cyclin-dependent kinases and tumor suppressor genes like p53, play critical roles in maintaining appropriate proliferation rates.
