Caspases are essential mediators of programmed cell death and are needed for both the induction of apoptosis as well as for aiding the degradation of cellular structures. Initiator caspases (such as Caspase-9) sense and respond to various signals including intracellular stress or binding of the death receptor to external ligands. Upon dimerization, initiator caspases gets activated, which follows cleavage of downstream effector caspases for carrying out the apoptotic program.
