Adapter protein for several members of the tyrosine kinase receptor family. Involved in multiple signaling pathways. May be involved in coupling from immunoreceptor to Ras signaling. Acts as a negative regulator of cytokine signaling in collaboration with CBL. Binds to EPOR and suppresses EPO-induced STAT5 activation, possibly through a masking effect on STAT5 docking sites in EPOR. Suppresses PDGF-induced mitogenesis. May induce cytoskeletal reorganization via interaction with VAV3. {ECO:0000269|PubMed:10374881, ECO:0000269|PubMed:12400014, ECO:0000269|PubMed:15378031, ECO:0000269|PubMed:9989826}. This is the function of SH2B2 (SH2B adaptor protein 2, Ensembl gene identifier ENSG00000160999).