52 pathways were significantly affected by downregulated genes in the cortex (p < 0.05), including retrograde endocannabinoid signalling pathway, dopaminergic synapse, insulin signalling pathway, cocaine addiction, Wnt signaling pathway, synaptic vesicle cycle, glutamatergic synapse, MAPK signalling pathway, long-term depression, cell cycle, amphetamine addiction, adipocytokine signalling pathway, Epstein-Barr virus infection, circadian rhythm, progesterone-mediated oocyte maturation, prostate cancer, protein processing in endoplasmic reticulum(Fig. 4f). The gene discussed is INS; the disease is cocaine dependence.