KEGG analysis (Nor vs. AD group) identified the significant enrichment pathways including apoptosis, MAPK signaling pathway, neuroactive ligand-receptor interaction, purine metabolism, dopaminergic synapse, serotonergic synapses, etc. The AD and AD_HFD groups were significantly enriched in the KEGG at dopaminergic synapse, synaptic vesicle cycle, cholinergic synapse, estrogen signaling pathway, neuroactive ligand-receptor interactions, MAPK signaling pathway, TNF signaling pathway, galactose metabolism, serotonergic synapse, starch and sucrose metabolism (Figures 3D,F). The gene discussed is TNF; the disease is Alzheimer disease.