For high-risk patients (children less than 12 months or children having CRP higher than 200 mg/L, severe anemia at disease onset, albumin level below 2.5 g/dl, liver disease, overt coronary artery aneurysms, macrophage activation syndrome or septic shock), we recommend IVIG (2 g/kg) combined with a bolus of methylprednisolone (30 mg/kg/day) and antiplatelet aspirin (3–5 mg/kg/day) (Figure 3). The gene discussed is CRP; the disease is macrophage activation syndrome.