Administration of exogenous IFNλ1 increased anti-fungal killing in CF neutrophils without increased reactive-oxygen species or neutrophil extracellular trap production.<h4>Interpretation</h4>CFTR modulators have led to improved clinical outcomes in CF related Aspergillus-related lung disease potentially due to partial restoration of the host antifungal epithelial type I/III interferon response. This evidence concerns the gene CFTR and lung disorder.