Subsequent KEGG pathway analyses indicated that the downregulated mRNAs participated in protein digestion and absorption, proximal tubule bicarbonate reclamation, peroxisome proliferator-activated receptor (PPAR) signaling pathway, cocaine addiction, and amyotrophic lateral sclerosis (Figure 1(e)), while the upregulated mRNAs were involved in phagosome, nucleotide-binding oligomerization domain (NOD)-like receptor signaling pathway, apoptosis, and lysosome, complement, and coagulation cascades (Figure 1(f)). This evidence concerns the gene PPARA and cocaine dependence.