Gab1 is a 115 kDa multiple docking protein that plays an essential role in cellular growth, transformation and apoptosis. Gab1 can be phosphorylated by multiple receptor tyrosine kinase (RTKs), including: insulin receptor (IR), platelet derived growth factor receptor beta] (PDGFRbeta]), hepatocyte growth factor/scatter factor receptor (HGFR/SFR or c Met), and epidermal growth factor receptor (EGF), as well as in response to cell cell adhesion. Gab1 is tyrosine phosphorylated on at least 16 si