The dual ETA/ETB receptor antagonist, bosentan reduces right ventricular hypertrophy in pulmonary hypertension in chronic hypoxic rats [47], but at present it is unclear whether the block of endothelin clearance and pulmonary vascular dilation by ETB receptors outweigh the beneficial effects of blocking both the ETA and ETB receptors in pulmonary hypertension due to hypoxia. The gene discussed is EDNRA; the disease is pulmonary hypertension.