RIPK1 and viral infectious disease: Two other proteins, Z-DNA-binding protein 1 (ZBP1), also known as DAI/DLM-1, and TIR-domain-containing adapter-inducing interferon-β (TRIF) are known to function upstream of RIPK3 and interact with RIPK3 through their RHIM (RIP homotypic interaction motif) domains to mediate necroptosis in response to viral infection or TLR signaling respectively10,11.