In a cohort of granulomatosis with polyangiitis (GPA) patients with vasculitis and kidney involvement, the authors found that circulating inflammatory endothelial cells, a kind of endothelial cells that are detached from the site of inflammation and are released into the peripheral blood, could release increased inducible nitric oxide synthase and neutrophil-activating chemokines such as epithelial neutrophil-activating peptide-78, growth-related oncogene-α, macrophage inflammatory protein-1α, and IL-8 and induced elevated neutrophil migration. Here, NOS2 is linked to granulomatosis with polyangiitis.