Interleukin-6 and its receptor during homeostasis, inflammation, and tumor growth.

This review focuses on describing the specific role of interleukin-6 within the network of inflammatory mediators in man. Sites of interleukin-6 synthesis, regulation of its expression, and the biological functions of this molecule are here outlined. The potential role of interleukin-6 as a diagnostic monitor is discussed. Particular attention is paid to experimental evidence that interleukin-6 and its receptor may be involved in the pathogenesis of autocrine tumor growth. A recently proposed therapeutical use of cytotoxic interleukin-6 fusion proteins in order to selectively, destroy certain interleukin-6 receptor bearing tumor cells is discussed in the light of the finding, that not only hepatocytes, but also normal peripheral blood monocytes express the interleukin-6 receptor.