In monocrotaline-induced pulmonary hypertension (PH), disease progression is associated with increased collagen synthesis and a decreased proportion of elastin in the PA media20, while transgenic S100A4/Mts1 mice that occasionally develop PH show upregulated expression of fibulin-5, an ECM component that controls elastic fiber assembly21. Here, ELN is linked to pulmonary arterial hypertension.