Aging and apoptosis control.

The phenomenon of aging is distinct from processes associated with advanced age known to increase risk of diseases, such as cancer. Furthermore, the process of aging is not necessarily related to phenomena such as in vitro replicative senescence; however, any unifying hypothesis of aging must account for all age-dependent phenomena, including senescence. It is proposed that apoptosis forms the ultimate protective process for preservation of phenotypic fidelity in multicellular organisms since it is the process by which the organism detects damage and replaces the defective cell. Time-dependent degeneration of apoptosis control is the rate-limiting step in the process of aging.