To ensure the reliability of the DEPs identified in the present study, we used qPCR and Western blot to validate two randomly selected DEPs, ANAPC7 and IFIT1, at the transcription and protein expression levels, respectively. In brief, ANAPC7 is an important constituent of the anaphase promoting complex/cyclosome, which is an E3 ubiquitin ligase that regulates the temporal progression of eukaryotic cells by mediating ubiquitination and subsequent 26S proteasome-mediated degradation of key cell cycle regulators.39 The downregulation of ANAPC7 is indicative of dysfunction of IPEC-J2 cells caused by PDCoV infection. IFIT1 is an innate immune effector molecule that can directly recognize viral single-stranded RNAs carrying a 5′-triphosphate group, thereby inhibiting the expression of viral mRNA.40 The upregulation of IFIT1 reveals that innate immune responses were activated in PDCoV-infected IPEC-J2 cells to combat with the invading virus. Through the validation of these two DEPs, we found that the obtained proteomics data were reliable and valid, and thus suitable for the subsequent bioinformatics analysis.