VCAN and pulmonary arterial hypertension: Among the binding partners of versican, hyaluronan (HA) and tenascin-C are elevated in the circulation of PAH patients.17, -19 Hyaluronan is a non-sulfated ECM GAG with a wide range of biological functions.20 It binds to versican through the N-terminal G1 domain and creates pericellular matrices that facilitate migration and proliferation of vascular smooth muscle cells.21 Both versican and HA accumulate in re-stenotic vascular lesions of the systemic circulation.21