Inhibition of endogenous estrogen synthesis withanastrozole reduces moderate and severe experimental PH and restores BMPR2signalling in female animals but not male.108 Inhibition of endogenous estrogen with anastrozole and fulvestrant alsohas beneficial effects in female BMPR2 mutant mice,110 and metformin can exert therapeutic effects in females SUGEN/hypoxiarats, in part via aromatase inhibition.111 Clinically, circulating estrogen levels are elevated in men andpostmenopausal women with IPAH.112,113. The gene discussed is BMPR2; the disease is idiopathic pulmonary arterial hypertension.