MMP9 and Marfan syndrome: Dale et al. [28] described similar elastic fiber fragmentation/disorganization in the aortas of a mgR murine model of MFS, as well as increased levels of MMP-2 and MMP-9, typical of MFS aortopathy, but also found higher levels of contractile proteins, suggesting a premature switch to a more mature contractile phenotype compared to wild-type mice.