Abstract: This invention relates to methods and compositions for the prevention or treatment of myelin disorders which involve modulating of Ulip/CRMP activity. In particular, a method for the prevention or treatment of myelin disorders is provided which comprises administering to a patient in need of such treatment a therapeutically effective amount of an agent which modulates Ulip/CRMP activity, and which can be a Ulip/CRMP protein, a nucleic acid coding for a Ulip/CRMP protein, an anti-sense sequence capable of specifically hybridizing with said nucleic acid, an antibody directed against the Ulip/CRMP protein, or an aptamer capable of binding said protein, and a pharmacologically acceptable carrier.