Grb2-associated binder 2, Gab2, belongs to the Gab/DOS family of scaffolding adaptors that include mammalian Gab1, Gab3, Drosophila Daughter of Sevenless (DOS), and Caenorhabditis elegans Suppressor of Clear 1 (SOC1) (Gu and Neel 2003; Wohrle et al. 2009). Gab1, the first identified member of this family of adaptors, was discovered in search of protein ligands for Grb2 SH3 domain (Holgado-Madruga et al. 1996). DOS was identified as a potential substrate for Corkscrew (Csw), the Drosophila ortholog of the SH2 domain containing protein tyrosine phosphatase 2 (Shp2) (Herbst et al. 1996). Gab2, the third member identified in this family, was initially cloned as a binding protein and substrate of Shp2 (Gu et al. 1998). Gab2 gene is located on human chromosome 11q14.1. Two other groups later cloned Gab2 by searching DNA database for protein with sequence homology to Gab1 (Nishida et al. 1999; Zhao et al. 1999). SOC1 was uncovered in a screen for...