Interestingly, we demonstrated that the combined action of IL6 and BMP9 may be a common and robust mechanism in cells from PAH donors representing the two most typical patient subtypes i) younger patients (before their 50s) with more severe hemodynamic impairments but better survival, and ii) an older subtype with more comorbidities [31]. This evidence concerns the gene GDF2 and pulmonary arterial hypertension.