While some studies suggest that enhancing BMP9 is beneficial, others report that genetic deletion or inhibition of BMP9 mitigates the onset and progression of PAH.8 BMP9 is recognized to be crucial for cardiovascular homeostasis and implicated in the development of pulmonary hypertension (PH), with its role appearing context- and time-dependent, particularly in the pulmonary endothelium. The gene discussed is GDF2; the disease is pulmonary arterial hypertension.