E2F1 and diabetes mellitus: Among them, CDK2, E2F1, CDKN1A, CDK1, CCND1, and CCNB1, which are located in the core genes in the PPI network, involve multiple pathways in the top ten, indicating that CDK2, E2F1, CDKN1A, CDK1, CCND1, and CCNB1 may be the key targets of compound therapy for DM.