ABSTRACT
Fifteen years have passed since interleukin 6 (IL-6) was cloned in 1986 [1-4]. During the last decade, many findings were made concerning the structure and function of IL-6 and its receptor, and the role of IL-6 in a variety of diseases. These findings together with a large volume of studies on many cytokines have greatly contributed to the establishment of a variety of concepts about cytokines in general: the establishment of pleiotropy and redundancy as properties of cytokine function, the cytokine receptor super family, the sharing of a signal-transducing receptor subunit among several cytokine receptors, the agonistic activity of certain soluble cytokine receptors, and the elucidation of the molecular mechanisms of inflammatory diseases.
