The remarkable advances in molecular and cell biology occurring over the past four decades have served the cause of surgical science well. Our understanding of basic disease mechanisms and insights into potential new therapeutic strategies have occurred at a staggering pace. Perhaps nowhere in surgical biology are these mechanistic insights and therapeutic prospects more evident than in research defining the cytokine mediators of inflammation, injury, and repair. These proteins are secreted to some degree by virtually all immune cell types as well as by a diverse array of other nucleated cells, and their functions encompass a regulatory role on and among many components of the immune system. Such intense interest is well deserved because abnormalities or dysregulation of tissue and wound repair as well as of natural (innate) or specific (acquired) immune function underlie much of the morbidity and mortality associated with surgical practice. Indeed, it is evident that the insights gained from the study of such inflammatory mediators cross virtually every specialty of surgery, from the acute sequelae of severe injury and invasive infection to the chronic manifestations of benign and malignant processes.