CYP19A1 and pulmonary arterial hypertension: These facts led us to plan and implement a phase IIa prospective parallel group study, the “GAIL” study: girls treated with an Aromatase Inhibitor and Leuprorelin, to investigate whether the combination of anastrozole and leuprorelin could significantly improve PAH in girls with EP and a compromised growth potential, compared to inhibition of puberty alone.