IL18 and infection: Although the duration of this early proinflammatory cytokines activation has not been previously described, in this study, we observed that, during single-PEDV infection, there is an up-regulatory effect on the part of IL18 that remains detectable by 3 DPI, while an opposite regulatory effect was observed on IL1-β, and no modulation of IL1-α or IL8 by 5 DPI was found.