Recent studies have shown that antagonizing transforming growth factor-β (TGF-β) by either TGF-β neutralizing antibodies or the angiotensin (Ang) II type 1 (AT1) receptor antagonist losartan can slow the progression rate of aortic root dilatation in an MFS mouse model [6] and in patients with MFS [13]. This evidence concerns the gene TGFB1 and Marfan syndrome.