The function of SOCS3 (suppressor of cytokine signaling 3, ENSG00000184557) is as follows. SOCS family proteins form part of a classical negative feedback system that regulates cytokine signal transduction. SOCS3 is involved in negative regulation of cytokines that signal through the JAK/STAT pathway (PubMed:16459330). Inhibits signal transduction by binding to transmembrane signaling receptors including IL6ST/gp130, LIFR, EPOR, INSR, IL12RB2, CSF3R/G-CSF-R and LEPR. Binding to JAK2 inhibits its kinase activity and regulates IL6 signaling. Suppresses fetal liver erythropoiesis. Regulates onset and maintenance of allergic responses mediated by T-helper type 2 cells (By similarity). Probable substrate recognition component of a SCF-like ECS (Elongin BC-CUL2/5- SOCS-box protein) E3 ubiquitin-protein ligase complex which mediates the ubiquitination and subsequent proteasomal degradation of target proteins (PubMed:15601820). Upon OSM stimulation, negatively regulates the JAK-STAT signaling mediated through type II OSM receptor complex by interacting directly with JAK1 (PubMed:16459330). {ECO:0000250|UniProtKB:O35718, ECO:0000269|PubMed:15601820, ECO:0000269|PubMed:16459330}.