The systemic inflammatory response as mediated by the cytokine network is undoubtedly complex. While inflammatory cytokines are indispensable in wound healing and the restoration of homeostasis, it is often the excessive activity of either proinflammatory or anti-inflammatory cytokines that causes injury to the host or renders the host immunocompromised, respectively. Central to the functional biology of cytokines in surgical injury and infections are the responses of immune cells to such insults. It is clear that immunocytes are the source of cytokine production, and these products possess important autocrine, as well as systemic activities. The ability to alter immunocyte function through extracellular hormonal influences or by manipulating intracellular signaling mechanisms are potential strategies for regulating the inflammatory cytokine response during injury.