Nature Communications, Published online: 20 June 2026; doi:10.1038/s41467-026-74452-8 Excessive Reactive oxygen species (ROS) production by neutrophils drives necrotizing inflammation of small blood vessels in Anti-neutrophil cytoplasmic antibody (ANCA)–associated vasculitis (AAV). However, the mechanism responsible for the dysregulated ROS production remains uncharacterized. Here, the authors report the contribution of soluble CD95L to neutrophil activation and ROS production and show that sCD9