The single-gene GSEA showed that MAPK3 may act on leukocyte migration in IBD and complement activation in IgAN, NFKB1 may affect the inflammatory response in IBD and endocytosis in IgAN, FDX1 may be involved in the adaptive immune response in IBD and cell activation in IgAN, and EPHX2 may function in the innate immune response in IBD and organic acid metabolic processes in IgAN. The gene discussed is MAPK3; the disease is inflammatory bowel disease.