Cytokines are integral to normal homeostasis and to the response to injury. The biologic activities and synergistic actions of these proteins continue to be elucidated. In moderate quantities, these proteins likely confer such beneficial effects as myelostimulation, activation of immune cells and reprioritization of metabolic processes to provide substrates important in combating the results of injury. Exaggerated or prolonged production of these proteins, however, may produce detrimental effects that lead to a poor outcome. Specific antagonists against cytokines offer potential therapy in these instances of aberrant cytokine response.