Cytokines are key mediators of immunity and inflammation. These protei
ns or glycoproteins act as communication signals between different pop
ulations of leukocytes but neither their effects nor their production
are restricted to immune cells. In the last few years many new cytokin
es and their effects have been discovered and it was agreed that when
the amino acid sequence of a new cytokine was established it would be
assigned the name interleukin (IL), with an added number. The detectio
n of cytokines in disease states promises to provide useful informatio
n for diagnostic purposes. The therapeutic utility of cytokines has be
en explored in many clinical and preclinical studies and in a wide var
iety of infectious diseases, autoimmune diseases and neoplasias. Since
the production of cytokines is modulated by several biological agents
such as hormones, prostaglandins and drugs, these may also serve as t
herapeutic targets for immunomodulation.