Cell death signal are transduced by death domain (DD), death effector domain (DED), and caspase recruitment domain (CARD) containing molecules. A novel protein that interacts with DED of caspase-8 and -10, and FADD was recently identified and designated DEDAF (for DED associated factor). DEDAF is identical to the transcriptional repressor RYBP. DEDAF interacts with FADD and aμgments the formation of CD95/FADD/caspase-8 complexes at the cytoplasm. DEDAF also interacts with DED-containing DNA biding protein (DEDD) in the nucleus, indicating it is involved in the regulation of both cytoplasmic and nuclear events of apoptosis.