RAN and neoplasm: Since metalloproteinases can be regulated via enzyme activation and inhibition, complex formation, and compartmentalization [40], it is quite possible that the intermediate metalloproteinases that act(s) between Ran and Met may not be regulated transcriptionally, and the identification of this metalloprotease is important to further our understanding of the interaction between Ran and Met and to provide a further therapeutic target for Ran-related neoplastic disease.