The cytokine network.

The availability of pure recombinant cytokines and molecular probes for their genes has generated an avalanche of scientific information. These data show that cytokines have a broad and overlapping range of cell regulatory activity both in vitro and in vivo. New factors are added to the cytokine list, and new functions reported for existing cytokines, with such frequency that it is difficult to retain an overall picture. With this problem in mind, a large wallchart was designed and was displayed at the second meeting of the British Cytokine Group* whose members pooled their collective knowledge, to list the known biological activities of these cytokines. This wallchart of cytokine activity, now referenced, is reproduced for Immunology Today. It is not a final list: new information and cytokines are continually reported and space has been left for readers to make their own additions. A neutrophil-activating peptide variously named monocyte-derived neutrophil chemotactic factor (MDNCF), neutrophil-activating factor (NAF), lymphocyte-derived neutrophil-activating peptide (LYNAP), which has been suggested as a candidate for interleukin 8 (IL-8), is included.