Fas-associated death domain protein (FADD) is an adaptor molecule that bridges the interactions between membrane death receptors and initiator caspases. Thus, the site of its action has always been expected to be the cytoplasmic death-inducing signaling complex (DISC). Recent evidence indicates that FADD primarily resides in the nucleus and appears to shuttle between nucleus and cytoplasm. In addition to its well-established role in transduction of apoptotic signals, FADD may also play a role in regulating genome surveillance and perhaps in other as yet unidentified cellular processes.