Indeed, global proteomic analysis identified impaired mitochondrial translation and associated defects in oxidative phosphorylation as the main biological processes altered in EZH2-depleted PAH-PASMCs, whereas downregulated genes in siEZH2-treated cells were mainly enriched in functions linked to cell-cycle progression and cell division, indicating that changes in mRNA expression provide only limited insight into the downstream mechanisms regulated by EZH2. The gene discussed is EZH2; the disease is pulmonary arterial hypertension.