Angiotensin II (Ang II) is a key effector peptide of the RAS (Figure 1) that can exert deleterious effects on the pulmonary vasculature, resulting in vasoconstriction via modulation of pulmonary vessel tone, inflammation, proliferation, and structural remodeling, which contribute to PAH development.1, 2, 3, 4, 13, 14, 15. This evidence concerns the gene AGT and pulmonary arterial hypertension.