Supporting the results from in vitro studies, a murine intranasal infection model using A. fumigatus conidia suggested that susceptibility to IA is associated with the levels of genes encoding IL-5 (a Th2 cytokine involved in B cell and eosinophil activation) and IL-17a (a Th17 inflammatory cytokine produced by T cells and NK cells). The gene discussed is IL17A; the disease is infection.