TBX20 and pulmonary arterial hypertension: Finally, mitochondrial respiration and gene array analyses in the current study provide evidence that under this model of SuCH, treprostinil does not alter mitochondrial respiration, but it does alleviate RV fibrosis and may do so via the modulation of fibrotic gene expression changes, possibly through TBX20, a novel player in the PAH RV identified in this study.