Prostaglandin research is one of the most explosive fields in the biological science, and there have been a number of international symposia on this subject. In planning the second Advanced Course in Erice (Sicily) at the "Ettore Majorana" center it was realized that large congresses might not represent the best way to facilitate communication within specialized areas of biologic and medical research. In fact small meetings where in depth discussion is confined to a limited number of scientists, are now generally considered successful vehicles of scientific information. With this in mind, we made an effort in collecting a number of experts in both experimental and clinical use of these important arachidonate metabolites. We have been very fortunate in bringing together a faculty of international authorities who contributed to the course with brilliant presentations and lively discussion. Thus, this book represents an up-to-date overview of the physiology and pharmacology of different products derived from arachidonic acid metabolism, associated with outstanding suggestions of their clinical potential. It is our hope that from this Advanced Course, and its resulting publication, new ideas concerning the physio­ pathological role of these compounds will arise together with new directions for future research. We are deeply indebted to NATO for its interest and generous support which made this Second Course a reality.