Proinflammatory cytokines are the principal intercellular mediators of the tissue reaction to trauma and infection. Members of IL-6 (Interleukin-6) hematopoietic cytokine family, that include IL-6, IL-11, LIF (Leukemia Inhibitor Factor), OSM (Oncostatin M), CNF (Ciliary Neurotrophic Factor), Cardiotrophin-1, and the recently described novel Neurotrophin-1/B-Cell Stimulatory Factor-3 play a particularly prominent role in orchestrating initiation and progression of inflammation, hematopoiesis, acute phase response, bone and heart development as well as neurogenesis. Their redundant effect is attributed to the shared use of the common signal transducing receptor chain GP130 (Glycoprotein-130). GP130 is homodimerized by IL-6 and IL-11 upon binding to their ligand-specific Alpha-receptors. The other cytokines of this family trigger the heterodimerization of GP130 with the LIFR (LIF Receptor) or the OSMR [...]