Background：

This gene encodes a member of the STAT-induced STAT inhibitor (SSI)， also known as suppressor of cytokine signaling (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)， CSF2/GM-CSF， and interferon (IFN)-gamma. 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-gamma action， which is required for normal postnatal growth and survival.