GAB3 (GRB2-associated binding protein 3) is a scaffolding/docking adaptor protein that functions as a signal transduction molecule downstream of receptor tyrosine kinases and non-RTK receptors 1. In cancer contexts, GAB3 mediates cell proliferation through activation of the Akt and Erk signaling pathways. GAB3 is significantly overexpressed in glioma tissues and colorectal cancer cells compared to normal tissues 23. In glioma, GAB3 promotes Akt activation and tumor cell proliferation; GAB3 knockdown suppresses both Akt signaling and cell growth, while overexpression enhances proliferation in vitro and tumor growth in vivo 2. Similarly, in colorectal cancer, GAB3 co-precipitates with p85 and SHP2 to activate both Akt and Erk pathways, driving cell proliferation 3. However, in lung adenocarcinoma and melanoma, GAB3 expression is downregulated and functions as a tumor suppressor; low GAB3 expression correlates with poor prognosis and immune evasion, while high expression predicts better clinical outcomes and enhanced anti-tumor immune responses 456. Additionally, GAB3 genetic variants may contribute to hypertension susceptibility in some populations 7, and GAB3 loci are associated with circulating metabolite regulation 8.