In contrast to apoptosis, necrosis has been traditionally thought to be a passive form of cell death with more similarities to an incident than to a suicide. Necrosis is the end result of a bioenergetic catastrophe resulting from ATP depletion to a level incompatible with cell survival and was thought to be initiated mainly by toxic insults or physical damage. It is morphologically characterized by vacuolation of the cytoplasm, mitochondrial swelling, dilatation of the endoplasmic reticulum (ER), and breakdown of the plasma membrane (Fig. 1) (6).