Moreover, GO and KEGG enrichment analysis selected seven potential AD-related proteins, namely death-associated protein kinase 1 (DAPK1), cyclin-dependent kinase 1 (CDK1), polo-like kinase (PLK1), insulin-like growth factor 1 (IGF1R), tyrosine-protein kinase Met (c-MET), epidermal growth factor receptor (EGFR) and dopamine receptor D4 (DRD4). The gene discussed is DRD4; the disease is Alzheimer disease.