Caspase family of cysteine proteases has been shown to play a key role in apoptosis. Caspase-1 (ICE, interleukin-1β-converting enzyme) is the mammalian caspase responsible for the proteolytic conversion of the proforms of interleukin-1β and IL-18 into active cytokines. Like other caspases, Caspase-1 itself is synthesized as a pro-enzyme that is cleaved during activation into a large (20 kDa) and small (10 kDa) subunits. The cellular role of caspase-1 appears limited to cytokine activation as they do not have obvious roles in apoptosis.