HDAC inhibitors such as scriptaid, suberoylanilide hydroxamic acid (SAHA), trichostatin A (TSA), and valproic acid (VPA) have been revealed to decrease Nox expression and ROS production via reducing histone activation traces (H3K4me3 and H3K9ac) in the Nox 2, 4, and 5 promoter regions, thus mitigating indices of PAH in the MCT rat model [126]. The gene discussed is HDAC9; the disease is pulmonary arterial hypertension.