Vascular inflammation is associated with oxidative stress which is one of key initiators of the development of vascular dysfunction in hypertension and diabetes.Identifying new regulators and intracellular signaling pathways involved in either production or scavenging of reactive oxygen species may help to reveal novel therapeutic targets in drug discovery.Our recent studies indicate that bone morphogenic protein 4 (BMP4) is likely to act as a common initiator for endothelial cell dysfunction involving up-regulation of COX-2 in hypertension and diabetes; targeting BMP4 instead of COX-2 could avoid COX-2 inhibition-related side effects when aiming to reduce vascular events (Circulation Research, 2010).