The intact PASMC treated with SOD siRNA was shown to obtain a hyperproliferative PAH phenotype and mitochondrial dysfunction while SOD2 overexpression or SOD-mimetic metalloporphyrin Mn(III)tetrakis (4-benzoic acid) porphyrin (MnTBAP) reverses this hyperproliferative phenotype both in vitro and in vivo [160,162]. Here, SOD1 is linked to pulmonary arterial hypertension.