Adapter protein that plays a role in intracellular signaling cascades triggered by activated receptor-type kinases. Plays a role in FGFR1 signaling. Probably involved in signaling by the epidermal growth factor receptor (EGFR) and the insulin receptor (INSR). Involved in the MET/HGF-signaling pathway. Identified in a complex containing FRS2, GRB2, GAB1, PIK3R1 and SOS1 (PubMed:11353842). Forms a tripartite complex containing GAB1, METTL13 and SPRY2 (By similarity). Within the complex interacts with METTL13 (By similarity). Interacts with GRB2 and with other SH2-containing proteins (PubMed:11353842). Interacts with phosphorylated LAT2 (By similarity). Interacts with PTPRJ (By similarity). Interacts (phosphorylated) with PTPN11 (By similarity). Interacts with HCK (By similarity). Expressed in the inner ear (at protein level) (PubMed:29408807). Expression is detected in the cochlear duct, spiral limbus region, efferent and afferent nerves, and in spiral ganglion neurons (at protein level) (PubMed:29408807). Phosphorylated on tyrosine residue(s) by the epidermal growth factor receptor (EGFR) and the insulin receptor (INSR). Tyrosine phosphorylation of GAB1 mediates interaction with several proteins that contain SH2 domains. Phosphorylated on tyrosine residues by HCK upon IL6 signaling (By similarity). Phosphorylated in response to FGFR1 activation. Belongs to the GAB family.