Enables cytokine activity and interleukin-6 receptor binding activity. Involved in several processes, including animal organ development; positive regulation of macromolecule metabolic process; and regulation of peptide hormone secretion. Acts upstream of or within with a positive effect on gene expression. Acts upstream of or within several processes, including cellular response to cytokine stimulus; regulation of gene expression; and salivary gland morphogenesis. Located in external side of plasma membrane and extracellular space. Part of interleukin-6 receptor complex. Is expressed in several structures, including adrenal gland; genitourinary system; gut; liver; and thymus. Human ortholog(s) of this gene implicated in several diseases, including artery disease (multiple); autoimmune disease (multiple); gastrointestinal system cancer (multiple); glucose metabolism disease (multiple); and periodontal disease (multiple). Orthologous to human IL6 (interleukin 6).