Contributes to interleukin-11 binding activity and interleukin-11 receptor activity. Involved in interleukin-6-mediated signaling pathway; intestinal epithelial cell development; and positive regulation of Notch signaling pathway. Acts upstream of or within several processes, including glycogen metabolic process; positive regulation of astrocyte differentiation; and regulation of Notch signaling pathway. Located in dendrite; external side of plasma membrane; and neuronal cell body. Is expressed in several structures, including alimentary system; brain; early conceptus; immune system; and reproductive system. Used to study rheumatoid arthritis and stomach cancer. Human ortholog(s) of this gene implicated in arteriosclerosis; hyper IgE recurrent infection syndrome 4; and hyperandrogenism. Orthologous to human IL6ST (interleukin 6 cytokine family signal transducer).