Adapter protein that associates with PIDD1 and the caspase CASP2 to form the PIDDosome, a complex that activates CASP2 and triggers apoptosis. Also recruits CASP2 to the TNFR-1 signaling complex through its interaction with RIPK1 and TRADD and may play a role in the tumor necrosis factor-mediated signaling pathway. Forms a complex named the PIDDosome with PIDD1 and CASP2. Interacts (via Death domain) with RIPK1 (via Death domain); the interaction is direct. Interacts with TRADD. Interacts with TNFRSF1A. The Death domain mediates the interaction with PIDD1 and the formation of a complex composed of 5 PIDD1 and 7 CRADD proteins which in turn probably recruit 7 CASP2 to form the PIDDosome. The Death domain mediates a direct interaction with the Death domain of RIPK1. The CARD domain mediates a direct interaction with CASP2.