The gene expression of DPP4 in AAA media and adventitia correlated with genes related to typical aneurysm disease processes, such as a large number of immune processes, ECM degradation and peptidase activity, angiogenesis and reactive oxygen species, whereas there was an inverse association with processes typically downregulated in aneurysm disease, including those related to SMCs. The gene discussed is DPP4; the disease is Vascular dilatation.