We next exposed PAH-PASMCs to escalating doses of EPZ-6438 (Tazemetostat) and GSK-126 for 48 h; two selective S-adenosyl methionine competitive inhibitors of histone methyl transferase EZH2 currently being evaluated in clinical trials for the treatment of cancer [17,18]. Here, EZH2 is linked to pulmonary arterial hypertension.