The white matter diseases and those of myelin, which involve the loss or dysfunction of oligodendrocytes in the brain and spinal cord, are among the most prevalent and disabling conditions in neurology, and are especially attractive targets for stem cell-based therapeutics. These disorders include the acquired diseases of myelin in adults, such as multiple sclerosis and white matter stroke, the congenital or early myelin loss of cerebral palsy and periventricular leukomalacia, and the hereditary and metabolic disorders of myelin loss, the pediatric leukodystrophies. In light of the wide range of disorders to which congenital hypomyelination or postnatal demyelination may contribute, and the relative homogeneity of oligodendrocytes and their progenitors, these conditions may be particularly appropriate targets for progenitor cell-based therapy. As a result, glial progenitor cells, which can give rise to astrocytes as well as myelinogenic oligodendrocytes (and hence are equivalently referred to as oligodendrocyte progenitor cells), have been extensively investigated as potential vectors for the restoration of myelin to the dysmyelinated brain and spinal cord (Goldman et al., 2012). These cells may be isolated from both adult and fetal
