NEDD1 and nicotine dependence: GSEA showed that NEDD1 expression was related to mitosis, chromosome segregation, cell cycle, etc., and KEGG enrichment analysis of NEDD1-related genes found that these genes were mainly related to neuroactive ligand-receptor interaction, motor proteins, metabolism of xenobiotics by cytochrome P450, retinol metabolism, drug metabolism--cytochrome P450, taste transduction, chemical carcinogenesis-DNA adducts, nicotine addiction ,maturity onset diabetes of the young, ascorbate and aldarate metabolism (P < 0.05, Figure 3D).