The expression of BMPRII significantly decreased in pulmonary artery isolated from patients with primary PAH and in some animal models of PAH induced by monocrotaline, chronic hypoxia or transgenic mice (SM22-rtTA X TetO7-MPR2delx4+) [6], [7], [8], [9], [10]. This evidence concerns the gene BMPR2 and pulmonary arterial hypertension.