BRCA1 and pulmonary arterial hypertension: It has been reported that endothelial cells from pulmonary arterial hypertension patients and pulmonary microvascular endothelial cells with reduced BMPR2 protein are more sensitive to DNA damage due to decreased amounts of BRCA1 and DNA Topoisomerase II binding protein 1, both of which have critical roles in relaying the DNA damage signal23,24.