{"type":"root","children":[{"type":"paragraph","children":[{"type":"text","value":"GRB2-associated-binding protein 1 (GAB1) is encoded by the GAB1 gene. GAB1 is a member of the IRS1-like multisubstrate docking protein family that transduces signals from various tyrosine kinases, such as Met, FGFR1, and EGFR. GAB1 plays a central role in cellular growth response, transformation, and apoptosis, as well as inflammatory responses. GAB1 is involved in the amplification of IL-6- induced MAPK pathway and promotes inflammation."}]},{"type":"paragraph","children":[{"type":"text","value":"Somatic mutations of the GAB1 gene have been detected in Breast and Colorectal Cancers and studies have shown that elevated expressions of GAB1 have been associated with Breast Cancer metastasis by dissociating the polarity-associated partitioning defective (PAR) complex and promoting epithelial-to-mesenchymal transition. Upregulation of GAB1 is an indication of unfavorable prognosis for Hepatocellular Carcinoma and Epithelial Ovarian Cancer. GAB1 overexpression has also been seen in Adult Acute Lymphoblastic Leukemia and Medulloblastomas. GAB1 can be used with a panel of immunohistochemical markers in the classification of Medulloblastomas into SHH (sonic hedgehog), WNT (wingless-type murine mammary tumor), or non-SHH/WNT subgroups."}]}]}