BMPR2 and pulmonary arterial hypertension: Regarding the possible role of DNA methylation on vascular injury, hypermethylation of the promoter of the bone morphogenetic protein receptor type-2 (BMPR2) gene has been shown to downregulate the expression of BMPR2 -whose impaired signaling is thought to promote PAH in SSc [35] -on microvascular endothelial cells (MVECs) isolated from affected skin of patients with SSc, therefore exposing them to apoptosis [36].