In 2000, Robert W. Thompson published a study titled “Targeted gene disruption of matrix metalloproteinase-9 (gelatinase B) suppresses development of experimental abdominal aortic aneurysms.” In this study, Thompson and his team used an elastase-induced AAA model to assess the role of MMPs in AAA progression. Here, MMP9 is linked to abdominal aortic aneurysm.