DNMT1 and pulmonary arterial hypertension: In addition to increased expression of DNMT (1, 3a, and 3b), our results revealed PAH patients as compared with healthy controls had higher total DNMT activity, which is driven by metabolites of one‐carbon metabolism, the polyamine pathway, and the Krebs cycle (Puleston et al., 2017; Solary et al., 2014; Stover, 2009).