IFI27 and bronchiolitis: Reliable biomarkers reflecting host antiviral responses and disease dynamics are still lacking.<h4>Methods</h4>We evaluated the expression of the interferon-stimulated genes IFI44L, IFI27, and RSAD2 in peripheral blood of infants hospitalized with RSV bronchiolitis at admission and discharge, and in healthy controls, using multiplex RT-qPCR.