For these patients, there is unequivocal evidence from randomized clinical trials showing the beneficial effects of parenteral prostacyclin analogues [40], initial phosphodiesterase-5 inhibitor/endothelin receptor antagonist combination therapy [41,42], and emerging agents such as the activin signaling inhibitor sotatercept [43,44], all of which have uncertain safety and efficacy in elderly patients hitherto classified as IPAH with co-morbidities. Here, INHBE is linked to idiopathic pulmonary arterial hypertension.