A previous report showed that interferon (IFN) γ-producing helper T (Th) cells and the Th1/Th2 ratio in peripheral blood were significantly higher in patients with AOSD than in healthy controls (HCs) and that the percentages of IFNγ-producing Th cells and the Th1/Th2 ratio in peripheral blood correlated significantly with the clinical activity score and serum IL-18 levels in patients with AOSD (35). Here, IFNG is linked to adult-onset Still disease.