Cytokines are soluble proteins produced by nucleated cells throughout the body.
They have wide ranging effects on cell growth and differentiation, mediating immune responses, haemopoiesis and tissue repair. Advances in recombinant DNA technology have led to a vast increase in knowledge of their biological properties and subsequently their use in human clinical trials. The use of human cytokines in feline medicine has been of limited success as the action of cytokines is often species restricted or their activity may be neutralized due to antibody formation. Recently, however, many feline cytokines have been cloned which raises the possibility of their future use in the management and prevention of feline disease. Ultimately, they may find widespread clinical uses including the treatment of cancer, cytopenias and viral infections and as vaccine adjuvants.