Caspases are a family of cysteine proteases that are particularly well known for their role in apoptosis. Caspases are translated as inactive zymogen precursor proteins. Initiator caspases have a large prodomain, and are cleaved to yield active enzyme in response to proapoptotic stimuli. Initiator caspases cleave and active effector (or executioner) caspases which cleave the substrates leading to programmed cell death. (Adapted from FBrf0215539).