The suppressor of cytokine signaling (SOCS) family members are negative regulators of cytokine signal transduction that inhibit the Jak/Stat pathway. Each SOCS family member contains a central SH2 domain and a conserved carboxy-terminal motif designated as the SOCS box. These proteins are important regulators of cytokine signaling, proliferation, differentiation, and immune responses. Low levels of SOCS3 are observed in lung, spleen and thymus and, like other SOCS family members, its expression is rapidly induced by a number of factors including interleukins, EPO, IFN-γ, CSF and TNF-α.
