DFF45/ICAD: ProductsDFF45 (DNA fragmentation factor 45 kDa subunit, also known as ICAD) is a 45 kDa member of the CIDE domain-containing family of proteins. Human DFF45 is 331 amino acids (aa) in length. It contains an N-terminal CIDE domain (aa 17-96) plus two caspase-3 cleavage sites (aa 117-118 and 224-225). DFF45 is a cytoplasmic protein that inhibits DFF40 DNAase. Normally, DFF45 and DFF40 form an enzymatically-inactive noncovalent heterodimer. Upon activation of the apoptotic cascade, DFF45 is cleaved into three fragments. These dissociate from DFF40 and induce DFF40 oligomerization and activation. Human DFF45 has two potential splice forms. One is truncated, and shows a seven aa substitution for aa 262-331; a second is extended, and shows a 45 aa substitution for the C-terminal five amino acids. Human DFF45 is 76% aa identical to mouse DFF45.