This gene encodes a member of the STAT-induced STAT inhibitor (SSI), also known as suppressor of cytokine signalling (SOCS), family. SSI family members are cytokine-inducible negative regulators of cytokine signaling. The expression of this gene can be induced by a subset of cytokines, including IL2, IL3 erythropoietin (EPO), GM-CSF, and interferon-gamma (IFN-γ). The protein encoded by this gene functions downstream of cytokine receptors, and takes part in a negative feedback loop to attenuate cytokine signaling. Knockout studies in mice suggested the role of this gene as a modulator of IFN-γ action, which is required for normal postnatal growth and survival.
Several recent viral studies have shown that viral genes, such as Tax gene product (Tax), encoded by HTLV-1, could hijack SOCS1 to inhibit host antiviral pathways, as a strategy to evade host immunity.