We propose that FGF9 overexpression in the airway epithelium protects the airway from IAV infection, likely by priming the cells to rapidly express high levels of IFNs and ISGs upon infection; however, this phenomenon precipitates an indirect consequence—rapid and robust infection of the alveolar cells, resulting in enhanced alveolar inflammation and exacerbated susceptibility to IAV disease. This evidence concerns the gene FGF9 and infection.