BMPR2 and pulmonary arterial hypertension: To this end, the StratosPHere 1 trial, a prospective biomarker trial, was designed to identify biological biomarkers representative of the BMPR2 pathway (Jones RJ, De Bie EM.D.D., Ng AYK, Dunmore BJ, Deliu N, Graf S, Lawrie A, Newman J, Polwarth G, Rhodes C, Hemnes A, West J, Villar SS, Upton PD, UK National Cohort Study of Idiopathic and Heritable PAH Consortium, the Uniphy Clinical Trials Network and Toshner MR: BMPR-II biomarkers for testing therapeutic efficacy in pulmonary arterial hypertension – novel findings from the StratosPHere 1 study, 2024+, under review).