IL18R1 and respiratory system disorder: To determine whether the observed association between IL18R1 levels and acute A(H7N9) disease severity could also be recapitulated in other respiratory diseases, we assessed IL18R1 gene expression in a second disease cohort of patients hospitalized with acute SARS-CoV-2 infection, MIS-C (multisystem inflammatory syndrome in children) or paediatric acute respiratory distress syndrome (pARDS) (Fig. 1a).