They also hypothesized that a constellation of factors such as persistent expression of the alpha-smooth muscle actin cytoskeleton, as well as high levels of the active form of matrix metallopeptidase-9, along with the role of inflammatory mediators and altered expression of N-cadherin family could be involved in the pathogenesis of hEDS/hypermobility spectrum disorder and the formation of the myofibroblast-like phenotype (32,34). Here, MMP9 is linked to Ehlers-Danlos syndrome, hypermobility type.