BMPR2 and pulmonary arterial hypertension: In PH pathophysiology: studies suggest that F2-isoP may function as a marker in the early stages of PAH (270) as F2-isoP is increased in both urine (271, 272) and plasma (272) in different subgroups of PAH (including IPAH, hereditary PAH and asymptomatic patients predisposed to PAH because of BMPR2 loss-of-function mutations) (273).