Proinflammatory cytokines, such as interleukin (IL)-1β, IL-6, IL-18, tumor necrosis factor-α (TNF-α), and interferon-γ (IFN-γ), have been found to be elevated during AOSD and are thought to be involved in the pathogenesis of AOSD [8–13]. This evidence concerns the gene IFNG and adult-onset Still disease.