FBN1 and Vascular dilatation: MFS is caused by mutations in the fibrillin-1 encoding gene (FBN1) and often results in aortic dilatation, myopia, bone overgrowth, and joint laxity.399–402 Fibrillin-1 is deposited in the ECM and interacts directly with latent TGF-β-binding proteins (LTBPs), keeping TGF-β sequestered and unable to exert its biological activity.