BMPR2 and pulmonary arterial hypertension: Following 20 weeks of HDM exposure, however, RVSP was increased in WT (33.54±1.57 versus 26.34±1.11) and in Bmpr2 ΔE2 (30.41±0.76 versus 26.67±0.51) mice compared to saline controls indicating the development of mild PAH in these animals (Figure 6A).