FN1 and isolated hemihyperplasia: After endothelial denudation, blood circulating plasma fibronectin becomes accessible and can be incorporated by SMCs into their native fibronectin ECM fibers, which together with cell‐secreted fibronectin serve as template for the assembly of other ECM proteins, such as collagen I.[75, 76] Since later stages of IH are characterized by increased ECM biosynthesis,[17] we investigated whether ECM assembly was also increased in our IH model.