GRAP2 belongs to the GRB2/Sem5/Drk family. GRAP2 is an adaptor-like protein has a part in leukocyte-specific protein-tyrosine kinase signaling. Similar to related family member, GRB2-related adaptor protein contains an SH2 domain flanked by two SH3 domains and it interacts with other proteins, for example GRB2-associated binding protein 1 (GAB1) and the SLP-76 leukocyte protein (LCP2), through its SH3 domains.