Influenza infection induced PGE2 to similar levels in plasma and BALF of Gabra1-IRES-cre; Ptger3flox, Phox2b-cre; Ptger3flox, Advillin-creER; Ptger3flox and Ptger3flox mice (Extended Data Fig. 9a), consistent with changes in PGE2 detection rather than PGE2 synthesis underlying the observed behavioural differences. The gene discussed is AVIL; the disease is influenza.