Considering the established Mendelian association of mutations in the BMP pathway with the disease, the central role of BMP/TGF-β signaling in PAH development,21,33,34,35,36 and the negative regulatory role of SMURF1 in BMP signaling,10,16 we hypothesized that inhibition of SMURF1 could augment BMP signaling and thereby offer a potential treatment for PAH. Here, TGFB1 is linked to pulmonary arterial hypertension.