BMPR2 and pulmonary arterial hypertension: Multiple signaling pathways have been associated with PAH pathogenesis including TGFβ/BMPR2, RhoA/RhoB kinase, serotonin, Notch, NO/cGMP, endothelin, Angiopoietin/Tie2, and the APLN/FGF2/FGFR1 signaling pathways [4, 21–23].