Clinical studies comparing PoPH to non-PoPH portal hypertensive liver disease have previously implicated a number of potential biomarkers and genetic risk factors that may be involved in PoPH pathogenesis, including a deficiency in circulating bone morphogenic protein type 9 (BMP9) and genetic variation in estrogen signaling and metabolism4,7–11. Here, GDF2 is linked to Pulmonary arterial hypertension associated with portal hypertension.