Cell death is a concept. Pathologists conceived cell death as a mechanism of disease (1). The death of cells (or the absence of appropriate cell death) is now recognized to have pathological and normal physiological importance. It is important for normal histogenesis (2-4) and cellular kinetics of healthy and malignant tissue (5). Cell death occurs through many pathways and has been classified generally as two distinct types, called apoptosis and necrosis, because they differ structurally and biochemically. These distinctions are now becoming blurred. Recently it has been realized that cell death exists as a continuum with apoptosis and necrosis at opposite ends of this continuum (6-9).