Because inhibition of the TGFβ–TAK1–MAPK pathway rescues abnormal proliferation and apoptosis of pulmonary artery smooth muscle cells isolated from BMPR2 mutant mice (Nasim et al., 2012), normalizing the decrease in SMAD6 expression may be therapeutic in PAH. This evidence concerns the gene TGFB1 and pulmonary arterial hypertension.