IL1B and COVID-19–associated multisystem inflammatory syndrome in children: Rheumatologic diseases can be stratified into three main categories: (1) autoinflammatory diseases, which are monogenic disorders often due to mutations in the IL-1 pathway; (2) acute inflammatory diseases, including reactive conditions such as Kawasaki disease (KD), multisystem inflammatory syndrome in children (MIS-C), acute rheumatic fever (ARF), reactive arthritis, etc.; and (3) autoimmune diseases characterized by the presence of adverse immune memory, such as lupus, myositis, scleroderma, and vasculitis [9].