Apoptosis is a controlled series of events in eukaryotic cells which leads to cell death. The process is also called programmed cell death or cell suicide. The term was coined in 1972 to distinguish this form of cell death from necrosis, which was associated with acute injury to cells. Apoptosis is a central part of normal development. Some of the events which occur in a cell undergoing apoptosis are the shrinkage of the cell, breakdown of their mitochondria (a specialized portion of the cell which functions in energy production), breakdown of DNA and protein, and the bubbling of the surface into "blebs". Ultimately specialized cells called macrophages engulf the cell. This latter process, called phagocytosis, differs from the phagocytosis seen in inflammatory responses.

Apoptotic death can be triggered by a wide variety of stimuli, and not all cells necessarily will die in response to the same stimuli. Damage to...