DPP4 and endothelial dysfunction: This is interesting because one of the transported proteins is the protease dipeptidyl peptidase-4 (DPP4) which is well known for cleavage and inactivation of our two most common incretins: glucose-dependent insulinotropic polypeptide (GIP) and proglucagon-derived peptide glucagon-like peptide-1 (GLP-1). The inactivation of GIP and GLP-1 by DPP-4 leads to several cardiometabolically adverse effects, including endothelial dysfunction, insulin resistance, and hyperlipidemia9.