Pulmonary arterial hypertension (PAH) is a type of high blood pressure in the lungs, in which blood vessels are narrowed, blocked or destroyed, causing the heart to work harder and, in time, results in cardiac weakness and failure. The disease is relatively rare, but affects an estimated 100,000 persons in the United States, and results in 20,000 deaths annually. There is no cure. In a study published May 4, 2022 in Science Translational Medicine, researchers at the University of California San Diego (UCSD) School of Medicine describe the underlying signaling pathway that results in PAH--and a novel monoclonal antibody therapy that blocks the abnormal blood vessel formation characterizing the disease. The article is titled “JAGGED-NOTCH3 Signaling in Vascular Remodeling in Pulmonary Arterial Hypertension.”