Remarkably, the cell-intrinsic death has been largely conserved
from worms to mammals (Baehrecke, 2002; Meier
et al., 2000). Just as in C. elegans, members of the B-cell
leukemia/lymphoma 2 (Bcl-2) family of proteins act as a
gatekeeper of apoptosis and the family of caspases (cysteine
aspartate proteases) execute the cell death program