IL18 and adult-onset Still disease: This may have affected the production of cytokines, but as shown in Supplementary Figure S1, the ROC-AUC of IL-18 in the untreated AOSD and adult HLH groups with a cutoff value of 18,550 pg/mL was 0.87 (95%CI: 0.78–0.94, 87.0% sensitivity, 92.1% specificity), and there was not a clear difference compared to the cases involving treated patients.