Recent studies show that SARS-CoV N protein inhibits type I IFN production through suppressing TRIM25-mediated RIG-I ubiquitination [171]. The MERS-CoV N protein also blocks IFN production by interacting with TRIM25 [171]. In addition, both MHV and SARS-CoV N proteins perturb the function of cellular protein activator of protein kinase R (PACT), which can bind to RIG-I and MDA5 to activate IFN production, and thus antagonize type-I IFN signaling [61]. These results indicate the important function of the CoVs N protein in modulating host innate immune response. Whether PEDV N protein targets TRIM25 or PACT should be investigated.