NOS3 and systemic sclerosis: Given that exhaled NO is diminished in patients with SSc and pulmonary hypertension [118], it is tempting to speculate that the inhibition of endothelial NOS in the lungs by ADMA, may contribute to pulmonary vasoconstriction and to the proliferation and hypertrophy of the tunica media, typically observed in SSc-related pulmonary vascular disease.