Four isoforms of caspase 10 (caspase 10a, 10b, 10c, and 10d) having the same prodomain but different mature large and small subdomain, have been described. Caspase 10 contains two death domains (DED) involved in linking to the death effector domain of the adapter protein FADD and recruiting the complex to TNFR1 and Fas. The inactive procaspase 10 is variably expressed in many tissues and cell lines as a cytosolic protein. The mature form of caspase 10 comprises two subunits, p23/p17 (splice isoforms) and p12. Interestingly, a caspase 9- dependent processing of caspase 10 by caspase 6 in cell-free extracts has recently been suggested. Caspase 10 can cleave and activate caspases 3, 4, 6, 7, 8, and 9. This is followed by cleavage of numerous key proteins, including the nuclear protein PARP.