KEGG analysis indicated that the high riskscore group showed enrichment in pathways such as the Synaptic vesicle cycle, Hematopoietic cell lineage, Nicotine addiction, GnRH secretion, and Neuroactive ligand-receptor interaction, while the low riskscore group displayed enrichment in pathways like Oxidative phosphorylation, Chemical carcinogenesis—reactive oxygen species, Protein export, IL-17 signaling pathway, and Basal transcription factors (Fig. 7b). This evidence concerns the gene GNRH1 and nicotine dependence.