Immune-mediated therapies can reduce the relapse rate in multiple sclerosis. However, there is no clear-cut evidence that any of these therapies substantially alter the long-term outcome for patients with progressive multiple sclerosis. The neurological disability that all too frequently accompanies multiple sclerosis is ultimately due to injury to target cells, principally oligodendroglia, within the nervous system. Recent data suggest that activation of leukemia inhibitory factor-receptor signaling is an important component of a neurobiological response that serves to limit the extent of immune-mediated injury. Therefore, inactivation of this pathway could provide a novel approach to the treatment of demyelinating disease.