In 2012, Shinya Yamanaka received the Nobel Prize for Medicine because of his ground breaking discovery that somatic cells can be transformed into a kind of embryonic stem cells, the so-called induced pluripotent stem cells, or iPS-cells. This iPS-technology enables the generation, in unlimited quantities, of all possible types of somatic cells from a patient to be used for transplantation in regenerative medicine or for extensive studies on the pathogenic mechanisms in a wide variety of genetic disorders. The PhD thesis by Arun Thiruvalluvan reports on research for both potential applications of iPS-cells. From iPS cells, obtained via skin fibroblasts of multiple sclerosis (MS) patients, large numbers of oligodendrocytes (specific myelin-producing brain cells) were generated. The idea that these autologous oligodendrocytes can contribute to repair of brain lesions in MS patients after implantation was successfully demonstrated in a non-human primate model of MS. Besides that, large numbers of nerve cells were produced from iPS cells of patients with the genetic neurological disorders SCA-3 (Spinocerebellar ataxia). Herewith, we obtained detailed insights into the pathogenic mechanisms underlying nerve cell degeneration in SCA3. Understanding of these mechanisms may enable the development of new therapeutical approaches for these, as yet untreatable, disorders.