 After binding IGF2 at the cell surface, IGF2Rs accumulate in forming clathrin-coated vesicles and are internalized.In the lumen of the "trans"-Golgi network, the IGF2R binds M6P-tagged cargo.The IGF2Rs (bound to their cargo) are recognized by the GGA family of clathrin adaptor proteins and accumulate in forming clathrin-coated vesicles.