Has antiviral and antiproliferative activities (PubMed:15254193). Produced by macrophages and stimulates the production of two enzymes: a protein kinase and an oligoadenylate synthetase (By similarity). During viral infection, mediates antiviral effect, either directly by inducing interferon-stimulated genes, either indirectly through stimulation of natural killer cells enabling them to control viral replication (PubMed:22912583). N-glycosylated (PubMed:15254193). Belongs to the alpha/beta interferon family.