In human cardiovascular pathogenesis, endoglin has been identified as the causal gene for hereditary hemorrhagic telangiectasia type I, classified by the clinical presence of recurrent epistaxis and spontaneous arterial venous malformation, sometimes followed by PH or PAH.67 Several epigenetic mechanisms regulating the expression of endoglin were reported in tumor conditions. This evidence concerns the gene ENG and pulmonary arterial hypertension.