BMPR2 and pulmonary arterial hypertension: We have also previously shown that mice with heterozygous in-frame deletion of Bmpr2 Exon2 (Bmpr2ΔEx2/+) have reduced endothelium-dependent vasodilator responses in the pulmonary vasculature [8], and approximately 30% of mice with conditional ablation of Bmpr2 in endothelial cells develop spontaneous pulmonary hypertension [11].