Automated description from the Alliance of Genome Resources (Release 4.0)
Enables cytokine receptor binding activity. Involved in cellular response to virus; lymphocyte activation involved in immune response; and positive regulation of immunoglobulin production. Acts upstream of or within positive regulation of cytokine production; positive regulation of natural killer cell differentiation; and positive regulation of natural killer cell mediated cytotoxicity. Predicted to be located in extracellular space. Is expressed in ductus deferens; epididymis; and testis. Human ortholog(s) of this gene implicated in asthma; common variable immunodeficiency; hepatocellular carcinoma; and systemic lupus erythematosus. Orthologous to human IL21 (interleukin 21).