Upon influenza infection of the recipients, GFP+ ILC2s were found to have downregulated GATA3 expression and upregulated IL-12Rβ2 and IL-18Rα, becoming so-called ex-ILC2s that produced IFNγ upon ex vivo stimulation with IL-12 and IL-18. The gene discussed is IL12RB2; the disease is influenza.