A new era of immunotherapy is arriving in medical therapeutics. Both immunosupresion and immunomodulation have advantages which the clinician must learn. In this review, the author describe several immunomodulators which include cytokines, interleukins, interferons, tumor necrosis factor, granulocyte colony-stimulating factor, erythropoietin, and immunoglobulins. Some of these therapeutics approaches are already with us, and some are at present in the experimental stage.