Aberrantly elevated high-mobility group box-1 (HMGB1), a critical inflammatory cytokine, with down-regulated BMPR2 and dysregulated mitochondrial fission due to the excessive activation of the GTPase dynamin-related protein 1 (Drp1) have been observed in PAH patients [58,59]. The gene discussed is BMPR2; the disease is pulmonary arterial hypertension.