DCN and abdominal aortic aneurysm: Decorin in the context of aortic aneurysm has a complex role: decorin associates with a lowered risk of rupture in murine abdominal aortic aneurysm (22), but while decorin serves a protective role in early in murine aneurysm formation it also correlates strongly with macrophage matrix metalloproteinase (MMP)-9 expression and lesion location (23).