The present invention provides methods and pharmaceutical compositions designed to intervene in this defective process and to promote or restore erythrocyte maturation in individuals suffering from a myelodysplastic syndrome. The methods involve maintaining the activity of GATA-1 by preventing sequestration of Hsp70 in the cytoplasm. Accordingly, it is an object of this invention to provide methods of restoring or increasing erythrocyte maturation in a subject suffering from a myelodysplastic syndrome by preventing proteolytic inactivation of GATA-1. In some embodiments, preventing is achieved by administering to the subject a compound that inhibits the XPO1 nuclear transporter.
