A significant association between serum IL-18 levels and disease activity has been reported in patients with AOSD and in those with sJIA.58 In patients with sJIA, serum IL-18 levels reflected disease activity and predicted the disease course.59 Furthermore, higher levels of IL-6 correlated with some clinical features, including fever and C-reactive protein (CRP), in patients with sJIA,60 with high serum levels of IL-1β and IL-6 also being found in patients with AOSD.61 This evidence concerns the gene CRP and adult-onset Still disease.