One major potential limitation of the present study is that although current studies contains in vivo APN depletion experiments and GLP-1-mediated regulation of APN expression in immature adipocytes, we could not conduct used genetic GLP-1 and APN animals to provide a direct evidence for the link between vascular aging and atherosclerosis and GLP-1/APN axis. Here, ANPEP is linked to atherosclerosis.