Programmed cell death is a major component of both normal development and disease. The roles of cell death during either embryogenesis or pathogenesis, the signals that modulate this event, and the mechanisms of cell demise are the major subjects that drive research in this field. Increasing evidence obtained both in vitro and in vivo supports the hypothesis that a variety of cell death programs maybe triggered in distinct circumstances. Contraryto the view that caspase-mediated apoptosis represents the standard programmed cell death, recent studies indicate that an apoptotic morphologycan be produced independent of caspases, that autophagic exe-cution pathways of cell death may be engaged without either the involvement of caspases or morphological signs of.
