Among the numerous genetic mutations, BMPR-II (Bone Morphogenic Protein Receptor Type II), which is expressed predominantly in the pulmonary endothelium and undergoes complex interactions with the TGF-β (Transforming Growth Factor β) signaling pathway, is one of the more remarkable factors responsible for causing PAH [105,123,124,125]. This evidence concerns the gene BMPR2 and pulmonary arterial hypertension.