In various models, PAH is ameliorated by blockade of TGFβ signaling through diverse mechanisms, including administration of neutralizing antibodies, antisense nucleotides, or TGFβ receptor kinase inhibitors, and by gene transfer of inhibitory SMAD (Varga and Pasche, 2009; Aschner and Downey, 2016). This evidence concerns the gene TGFB1 and pulmonary arterial hypertension.