Recent advances in our understanding of the fundamental role of bioactive lipids in normal and abnormal physiology was the theme of the XVlth International Spring Sympo- 6-9, 1996 at the George Washington University School sium on Health Sciences held on May of Medicine in Washington, D.C. Over 250 participants shared their latest findings on fundamental mechanisms in lipid metabolism, transport, and signal transduction. Most of the papers presented at the plenary sessions have been collected in this volume, which is divided into seven parts. The focus of Part I is on the new roles that fatty acids and esters play in cellular function. These activities include regulation of gene expression, control of eicosanoid-me- diated responses, and intracellular calcium sequestration. Most biological effects of fatty acids, esters, and phospholipids are transmitted via the interaction of these lipid molecules with specific lipid binding proteins. The chapters in Part II detail the involvement of these in the transport of fatty acids, fatty acyl CoA esters, and phospholipids, and in the proteins modulation of the fatty acid-induced activation of the peroxisome proliferator-activated receptors. The study of arachidonic acid metabolism continues to be the subject of intense interest and research. A number of studies in Part III deal with the substantial differences between the constitutive prostaglandin H synthase isozyme (PGHS-l or COX-I) and the inducible form PGHS-2 (COX-2) regarding compartmentation, control, and expression.