rance, 0.05 Da; validation based on, q-value. To guarantee the accuracy of the MS data analysis, the cutoff value for the peptide and protein confidences was set to >95% and >1.20, respectively, coupled with a false discovery rate (FDR) of ≤1% for peptide and protein identifications. The t test function in the R language software was applied to calculate the p-value of the expression difference of cellular proteins between mock- and PDCoV-infected IPEC-J2 cells, and