PLP2 and infection: Similar to RIG-I, the different effects on canonical NF-κB and IRF7 induced by PEDV non-S-INDEL infection observed between the current and previous studies may be due not only to S protein but also other proteins, such as the Nsp1, papain-like protease 2 (PLP2), N, and M proteins expressed during the acute phase of PEDV infection33,60–62.