Claspin is cleaved by caspase-7 during the initiation of apoptosis following DNA damage (Clarke et al., 2005). Claspin is cleaved at a single aspartate residue into a large N-terminal fragment and a smaller C-terminal fragment that contain different functional domains. Only the large N-terminal fragment retains Chk1 binding activity. The smaller C-terminal fragment associates with DNA and inhibits the DNA-dependent phosphorylation of Chk1 associated with its activation indicating that cleavage of Claspin by caspase-7 inactivates the Chk1 signaling pathway (Clarke et al., 2005).