SMAD3 and triple-A syndrome: For this reason, we decided to screen AAA patients for variants in the transforming growth factor-beta pathway genes EFEMP2, FBN1, SMAD3, TGBF2, TGFBR1, TGFBR2, smooth muscle cells genes ACTA2, MYH11 and MYLK, as well as the vascular Ehlers–Danlos gene COL3A1, which is associated with vascular fragility (Pepin et al. 2000).