Interestingly, we identified that individual class I HDAC isoforms regulate molecules related to Wnt/β-catenin (LEF1), Hippo (YAP1), flow-responsive (KLF2) and insulin signaling (GLUT4) pathways, which plays an important role in driving PAH pathogenesis. The gene discussed is HDAC9; the disease is pulmonary arterial hypertension.