GDF2 and pulmonary arterial hypertension: With regard to the interaction between GDF2 (BMP9) and BMP10, circulating BMP9 was encoded by the GDF2 gene [41], and one study indicated that despite there being no differences in plasma BMP10 levels in male PAH patients compared to a control group, the plasma BMP10 levels in female PAH patients were significantly lower than the control females [42].