The interleukin-6 (IL-6) cytokine family, including IL-6, IL-11, leukemia inhibitory factor (LIF), oncostatin M (OSM), ciliary neurotrophic factor (CNTF), cardiotrophin-1 (CT-1), and B-cell stimulatory factor 3, are also known as gp130 cytokines because they all share gp130 as a common transducer protein within their functional receptor complexes. In the case of IL-6, binding of the ligand to its specific a-receptor (IL-6Ra/CD126) induces dimerization of gp130, activation of the gp130-associated Janus kinases Jak1, Jak2 and Tyk2 and phosphorylation of gp130 at cytoplasmic tyrosine residues. These phosphotyrosines serve as docking sites for SH2-domain-containing proteins such as STAT1, STAT3, the protein tyrosine phosphatase SHP2 and the suppressor of cytokine signaling 3 (SOCS3). The subsequently tyrosine phosphorylated STAT homo- or heterodimers translocate to the nucleus where they bind to enhancer sequences of IL-6-inducible genes. Both IL-6Ra and gp130 have soluble forms. Although soluble gp130 inhibits the effect of IL-6, the soluble IL-6Ra promotes the effect of IL-6.Synonyms: IL-6R-beta, IL6 receptor beta, Interleukin-6 receptor subunit beta