As other mechanisms, insulin-degrading enzyme (Kurochkin et al., 2018), insulin resistance (Sedzikowska and Szablewski, 2021), and acylated glucagon-like peptide 1 (GLP-1) analog have been proposed to link DM and AD, and the role of APOE4 between them is being investigated. The gene discussed is APOE; the disease is Alzheimer disease.