Caspase family of cysteine proteases plays a key role in apoptosis. Caspase-10 is expressed in many tissues and cell lines. Similar to other caspases, caspase-10 is also synthesized as an inactive pro-enzyme that is processed in cells undergoing apoptosis. Four isoforms of caspase-10 have been identified: caspase-10a (Mch4), caspase-10b (FLICE2), caspase-10c and caspase-10d. They have the same prodomain but different mature large and small subdomains. Activated caspase-10 activates caspase-3,-4,-6,-7,-8, and –9, which are then involved in proteolytic cleavage of many cellular proteins. Caspase-10 has been shown to be involved in the Fas and TNFR1 - induced apoptosis.