Adapter protein that associates with PIDD1 and the caspase CASP2 to form the PIDDosome, a complex that activates CASP2 and triggers apoptosis (PubMed:9044836, PubMed:15073321, PubMed:16652156, PubMed:17159900, PubMed:17289572). 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 (PubMed:8985253). Forms a complex named the PIDDosome with PIDD1 and CASP2 (PubMed:9044836, PubMed:8985253, PubMed:15073321, PubMed:16652156, PubMed:17159900, PubMed:17289572). Interacts (via Death domain) with RIPK1 (via Death domain); the interaction is direct (PubMed:9044836). Interacts with TRADD (PubMed:8985253). Interacts with TNFRSF1A (PubMed:8985253). Constitutively expressed in most tissues, with particularly high expression in adult heart, testis, liver, skeletal muscle, fetal liver and kidney. 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 (PubMed:17289572). The Death domain mediates a direct interaction with the Death domain of RIPK1 (PubMed:9044836). The CARD domain mediates a direct interaction with CASP2. The disease is caused by variants affecting the gene represented in this entry.