KEGG enrichment analysis results revealed that they were significantly related to a variety of PD-related pathways such as cocaine addiction, dopaminergic synapse, amphetamine addiction, serotonergic synapse, ECM-receptor interaction, alcoholism, tyrosine metabolism, Parkinson's disease, PPAR signaling pathway, and synaptic vesicle cycle (Figure 10(d)). The gene discussed is PPARA; the disease is cocaine dependence.