LCN2 and bacterial infectious disease: In this study, we present the diagnostic RF models based on five-gene host signature with RefValue (LCN2, PI3, SLPI, IFI27 and IFIT2) in whole blood samples that could correctly distinguish B/V infections in febrile children (85.3% accuracy, 95.1% sensitivity, 80.0% specificity), meeting/exceeding the Foundation for Innovative New Diagnostics (FIND)-sponsored expert guidelines for diagnostic sensitivity/specificity to differentiate between bacterial and non-bacterial infections (35).