GSEA analysis showed that axon guidance and PPAR signaling pathway enriched in KEGG were up-regulated in IDD, while cytokine-cytokine receptor interaction, chemokine signaling pathway, toll-like receptor signaling pathway, Nod-like receptor signaling pathway, bladder cancer, and cytosolic DNA-sensing pathway were down-regulated in IDD (Figure 3). The gene discussed is PPARA; the disease is intervertebral disk degenerative disorder.