Under specific pathophysiological conditions, including oxidative stress or viral infection, the deubiquitinase CYLD removes K63-linked ubiquitin chains from RIPK1, leading to Complex I disassembly and transition into the cytosolic Complex IIa, which is composed of FADD, TRADD, procaspase-8, and deubiquitinated RIPK1. The gene discussed is RIPK1; the disease is viral infectious disease.