Mitochondria have been discovered to exert an important, perhaps essential, role in the
process of apoptosis (for review see Refs. 1 and 2). It appears that one rate-limiting step of
apoptosis is an increase in the permeability of the inner and/or outer mitochondrial
membrane accompanied by the release of proteins normally confined to the intermembrane
space. As a result, mitochondria or mitochondrial intermembrane proteins are essential for
the induction of nuclear apoptosis in vitro in most, if not all, experimental systems of …