Adapter protein that provides a critical link between cell surface growth factor receptors and the Ras signaling pathway. Associates (via SH2 domain) with activated EGF and PDGF receptors (tyrosine phosphorylated) (By similarity). Interacts with PDGFRA (tyrosine phosphorylated); the interaction may be indirect (By similarity). Also associates to other cellular Tyr-phosphorylated proteins such as SIT1, IRS1, IRS4, SHC and LNK; probably via the concerted action of both its SH2 and SH3 domains. It also seems to interact with RAS in the signaling pathway leading to DNA synthesis. Interacts with SOS1. Forms a complex with MUC1 and SOS1, through interaction of the SH3 domains with SOS1 and the SH2 domain with phosphorylated MUC1. Interacts with phosphorylated MET (By similarity). Interacts with phosphorylated TOM1L1 (By similarity). Interacts with the phosphorylated C-terminus of SH2B2 (By similarity). Interacts with phosphorylated SIT1, LAX1, LAT, LAT2 and LIME1 upon TCR and/or BCR activation (By similarity). Interacts with NISCH, PTPNS1 and REPS2 (By similarity). Interacts with syntrophin SNTA1 (By similarity). Interacts (via SH3 domains) with REPS1 (By similarity). Interacts (via SH3 domains) with PIK3C2B. Interacts with CBL and CBLB (By similarity). Interacts with AJUBA and CLNK (By similarity). Interacts (via SH2 domain) with TEK/TIE2 (tyrosine phosphorylated) (By similarity). Interacts with SHB, INPP5D/SHIP1, SKAP1 and SKAP2 (By similarity). Interacts with PTPN11 (By similarity). Interacts with PRNP (By similarity). Interacts with RALGPS1. Interacts with HCST (By similarity). Interacts with KDR (By similarity). Interacts with FLT1 (tyrosine-phosphorylated) (By similarity). Interacts with GAPT and PTPRE. Interacts (via SH2 domain) with KIF26A. Interacts (via SH3 2) with GAB2. Interacts with ADAM15 (By similarity). Interacts with THEMIS2 (By similarity). Interacts (via SH2 domain) with AXL (phosphorylated). Interacts (via SH2 domain) with KIT (phosphorylated). Interacts with PTPRJ and BCR. Interacts with PTPN23. Interacts with FLT4 (tyrosine phosphorylated). Interacts with EPHB1 and SHC1; activates the MAPK/ERK cascade to regulate cell migration. Part of a complex including TNK2, GRB2, LTK and one receptor tyrosine kinase (RTK) such as AXL and PDGFRL, in which GRB2 promotes RTK recruitment by TNK2. Interacts (via SH2 domain) with CSF1R (tyrosine phosphorylated). Interacts with ERBB4. Interacts with NTRK1 (phosphorylated upon ligand-binding). Interacts with PTK2/FAK1 (tyrosine phosphorylated). Interacts with PTK2B/PYK2 (tyrosine phosphorylated). Interacts (via SH2-domain) with SCIMP; this interaction is dependent on phosphorylation on SCIMP 'Tyr-69' (By similarity). Interacts (via SH3 domains) with GAREM1 isoform 1 (via proline-rich domain and tyrosine phosphorylated); the interaction occurs upon EGF stimulation (By similarity). Interacts with DAB2 (By similarity). Interacts with TESPA1 (By similarity). Interacts with PLCG1, LAT and THEMIS upon TCR activation in thymocytes; the association is weaker in the absence of TESPA1 (By similarity). Interacts with CD28 (By similarity). Interacts with RAB13; may recruit RAB13 to the leading edge of migrating endothelial cells where it can activate RHOA (By similarity). Interacts with ASAP3 (phosphorylated form) (By similarity). Interacts (via SH2 domain) with PTPRH (phosphorylated form) (By similarity). Interacts with PTPRO (phosphorylated form) (By similarity). Interacts with PTPRB (phosphorylated form) (By similarity). Interacts (via SH3 domain 2) with PRR14 (via proline-rich region). Interacts with FCRL6 (tyrosine phosphorylated form). Interacts with RHEX (via tyrosine-phosphorylated form) (By similarity). Interacts with DENND2B (By similarity). Interacts with SPRY2 (By similarity). Interacts with LRRC8A (By similarity). The SH3 domains mediate interaction with RALGPS1 and SHB. Belongs to the GRB2/sem-5/DRK family.