As the aneurysm developed, SMAD4 KD mice displayed typical pathological performances of the inherited predispose to TAAD, including aortic diameter increase, plaque accumulation, aortic wall thickening, monocytes infiltration and medial degeneration characterized by destructive vascular matrix remodeling (Fig. 8B-E). The gene discussed is SMAD4; the disease is aneurysm.