Additionally, a number of other aspects of the molecular pathomechanism of MFS have been characterized in recent years, including evidence that haploinsufficiency for fibrillin-1 contributes to failed microfibrillar assembly and the development of disease [10], [11], endothelial dysfunction and compromised eNOS/Akt signaling [12]–[14], and alterations in the biosynthesis of fibrillin-1 rich microfibrils [15], [16]. This evidence concerns the gene FBN1 and endothelial dysfunction.