Death-associated protein kinase (DAPK1) is a Ca2+/calmodulin-regulated serine/threonine kinase that participates in a wide range of apoptotic signals including interferon-?, tumor necrosis factor ?, Fas, activated c-Myc, and detachment from the extracellular matrix. In addition to the kinase domain and calmodulin regulatory segment, DAPK1 also has eight ankyrin repeats, a cytoskeleton binding region, and a conserved death domain . Deletion of the calmodulin-regulatory domain generates a constitutively active mutant kinase. Ectopic expression of wild-type DAPK1 induced cell death in HeLa cells. Conversely, expression of a catalytically inactive mutant protected cells from interferon-?-induced cell death . The catalytic domain of DAPK1 has very high sequence similarity to vertebrate myosin light chain kinase (MLCK) and a RXX(S/T)X motif derived from myosin light chain protein was shown to be phosphorylated in vitro by DAPK1 .Epigenetic silencing of DAPK1 by promoter methylation has been observed in cases of chronic lymphocytic leukemia .