Enables cytokine activity. Involved in positive regulation of DNA-binding transcription factor activity; positive regulation of immunoglobulin production; and positive regulation of transcription, DNA-templated. Acts upstream of or within positive regulation of peptidyl-tyrosine phosphorylation. Located in extracellular space. Is expressed in colon; thymus; and thymus primordium. Human ortholog(s) of this gene implicated in asthma. Orthologous to human IL5 (interleukin 5). [provided by Alliance of Genome Resources, Apr 2022]