OPALIN and necrotizing enterocolitis: In addition to genes within the enriched biological processes, the changes in expression of several other disease-specific Si-NEC and Co-NEC DEGs identified by RNA-seq were further verified by qPCR, including upregulation of IER3 and TXNIP (p < 0.01 for both genes) and downregulation of OPALIN in Si-NEC pigs (p < 0.05) and upregulation of TF in Co-NEC pigs (p = 0.005, Fig. 3d).