VDVAD has been shown to be a preferred cleavage site for caspase-2. Caspase 2 is a very versatile caspase with multiple functions. It is a member of the family of cysteine proteases called caspases that cleave proteins only at an amino acid following an aspartic acid residue. Within this family, caspase 2 is part of the Ich-1 subfamily. Caspase 2 has a similar amino acid sequence to initiator caspases, including caspase 1, caspase 4, caspase 5, and caspase 9. It is produced as a zymogen with a long pro-domain. Pro-caspase-2 contains two subunits, p19 and p12. Caspase 2 associates with several proteins involved in apoptosis via its CARD domain, including RAIDD, ARC, and DEFCAP. Together with RAIDD and PIDD/LRDD, caspase 2 has been shown to form the PIDDosome, which may serve as an activation platform for the protease, although it may also be activated in the absence of PIDD. Caspase 2 may also form a complex with the DNA-PKcs and PIDD/LRDD, which is involved in DNA repair after DNA damage.