Merlin is closely related to ezrin, radixin and moesin (ERMs) — membrane–cytoskeleton-associated proteins that belong to the protein 4.1 superfamily. Although merlin is the only member of the merlin/ERM subfamily that is known to function as a tumour suppressor, common subcellular localization, shared interacting partners and physical interaction between merlin and the ERMs indicate that functional overlap exists. Mouse models indicate that merlin inactivation might have an unappreciated role in human cancer aetiology. So, could the ERM proteins also have a role in cancer development?