In their study, Han et al. [58] examined the associations between IL-33/ST2 levels and clinical manifestations of patients with AOSD and found that the levels of serum IL-33 and soluble ST2 were significantly elevated in patients with active AOSD compared with patients with RA or healthy controls; accordingly, serum IL-33 levels fell when disease activity declined during follow-up, after treatment. The gene discussed is IL33; the disease is rheumatoid arthritis.