The invention is based on CGI-27 (named Memo for mediator of ErbB2-dependent cell motility) and its role in cell motility. The invention provides methods of inhibiting cell migration, particularly late phase cell migration e.g. which is induced by signals from the EGF-R. Also provided a related methods and materials for identifying and using inhibitors and other molecules, such as Memo binding partners, which may be used in modulating cell motility.