Mitochondria: execution central.

Mitochondria play an essential function in eukaryotic life and death. They also play a central role in apoptosis regulation, reflected by the convergence of Bcl-2 family members on the mitochondrial outer membrane, and the presence of 'death factors' in the intermembrane space. Mitochondrial structure and function must be taken into consideration when evaluating mechanisms for cytochrome c release. The core machinery for caspase activation is conserved from Caenorhabditis elegans to man, and we consider parallels in the role of mitochondria in this process.