DNMT1 and scleroderma: Further, since expression of all three DNMT mRNA and total DNMT activity increases in leukocytes and in extracellular vesicles of scleroderma-associated and idiopathic PH patients (24), we propose that release of increased arterial and alveolar DNMT1 and DNMT3B in extracellular vesicles perhaps has paracrine-like action.