According to KEGG analysis, relapse‐related differentially expressed proteins were mainly enriched in the MAPL signaling pathway, the intestinal immune network for IgA production and inflammatory bowel disease; the severity‐related differentially expressed proteins were mainly enriched in cytokine–cytokine receptor interaction, the IL‐17 signaling pathway and the chemokine signaling pathway (Figure 2F,G). Here, IL17A is linked to inflammatory bowel disease.