Suppressor of cytokine signaling 3 (SOCS3) is a member of the STAT-induced STAT inhibitor (SSI), also known as suppressor of cytokine signaling (SOCS), family that negatively regulates cytokine signal transduction. SOCS3 is feedback inhibitors of the Janus kinase (JAK) and signal transducer and activator of transcription (STAT) signaling pathway. Inhibits cytokine signal transduction by binding to tyrosine kinase receptors including gp130, LIF, erythropoietin, insulin, IL12, GCSF and leptin receptors. SOCS3 also can bind to JAK2 kinase inhibits its kinase activity and nhibits insulin signaling in adipose tissue and the liver. Besides, Glycoprotein 130 (gp130) has been identified as an interactor of SOCS3, thus a binding ELISA assay was conducted to detect the interaction of recombinant mouse SOCS3 and recombinant mouse gp130. Briefly, SOCS3 were diluted serially in PBS, with 0.01% BSA (pH 7.4). Duplicate samples of 100uL were then transferred to SOCS3-coated microtiter wells and incubated for 2h at 37℃. Wells were washed with PBST and incubated for 1h with anti-SOCS3 pAb, then aspirated and washed 3 times. After incubation with HRP labelled secondary antibody, wells were aspirated and washed 3 times. With the addition of substrate solution, wells were incubated 15-25 minutes at 37℃. Finally, add 50µL stop solution to the wells and read at 450nm immediately. The binding activity of of SOCS3 and gp130 was shown in Figure 1, and this effect was in a dose dependent manner.