MUL1 and inflammatory bowel disease: 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).