In Marfan patients, mouse models for Loeys-Dietz syndrome and transverse aortic constriction (TAC), losartan treatment prevents aortic aneurysm formation accompanied by reduced TGF-β1 levels in patients with Marfan syndrome, and reduced TGF-β1 and TGF-β2 levels in Loeys-Dietz syndrome and TAC mice30, 36, 46, 47. This evidence concerns the gene TGFB2 and persistent truncus arteriosus.