Aortic aneurysms are subdivided anatomically into thoracic aortic aneurysms and AAAs, and although there are some differences in the underlying pathogenesis, both are characterized by fragmented and diminished elastin fibers.22 We therefore investigated whether miR-181b inhibition prevents aneurysm formation within the ascending and descending thoracic aortae in our Ang II–infused, Apoe−/− mouse model. The gene discussed is APOE; the disease is thoracic aortic aneurysm.