They found that glucose-6-phosphate dehydrogenase (G6PD), the rate-limiting enzyme in the pentose phosphate pathway (which is upregulated under pulmonary hypertension), upregulates DNMT activity, which decreases the expression of genes encoding vascular-protective proteins, including SOD2 and nitric oxide synthase 3 (NOS3), ultimately promoting the pathogenesis of PH [51]. This evidence concerns the gene DNMT1 and pulmonary arterial hypertension.