Suppressor of cytokine signaling 4 is a protein that in humans is encoded by the SOCS4 gene.
The protein encoded by this gene contains a SH2 domain and a SOCS BOX domain. The protein thus belongs to the suppressor of cytokine signaling (SOCS), also known as STAT-induced STAT inhibitor (SSI), protein family. SOCS family members are known to be cytokine-inducible negative regulators of cytokine signaling. Two alternatively spliced transcript variants encoding the same protein have been found for this gene.