Book excerpt: Endothelin-1 (ET-1), a peptide discovered in 1988, is one of the most potent contractors of vascular smooth muscle. Since their discovery, ETs have generated enormous interest in the scientific and pharmaceutical communities, prompting extensive research. This book addresses the latest findings regarding ETs-how they function, their effects, and characteristics. Divided into five sections, the book covers: endothelin receptors, endothelin synthesis and degradation, endothelin pathophysiology, ligand structure and activity relationships, and clinical studies. Pharmacologists, toxicologists, and pharmaceutical researchers will all benefit from this thorough review of current findings and future directions in ET research.