More importantly, we demonstrated that blockade of EZH2 methyltransferase activity using EPZ-6438 and GSK126 markedly impedes the pro-proliferative and apoptosis-resistant state of PAH-PASMCs; the findings were recapitulated by EZH2 knockdown using siRNAs. The gene discussed is EZH2; the disease is pulmonary arterial hypertension.