May play a role in the regulation of immune cell function. Cytokine that imparts cellular protection against viral infection in a species-specific manner. Activates the interferon-stimulated response element signaling pathway. It is able to directly modulate cytokine release from monocytes and dendritic cells. Binds heparin. Expressed in keratinocytes, monocytes and in resting dendritic cells. By viral infection, upon exposure to double-stranded RNA, or upon treatment with either interferon-gamma or interferon-beta. Belongs to the alpha/beta interferon family.