Recent advances in nuclear reprogramming technology allow the transformation of terminally differentiated, adult cells into induced pluripotent stem cells whose phenotype is indistinguishable from that of embryonic stem cells. This leap forward enables the creation of patient-specific pluripotent cell lines that carry disease genotypes. These cell lines could be used both as in vitro models for the study of disease and as potential sources of material for cell replacement therapy. Ultimately, a greater understanding of the process by which cellular identity is shaped and altered may allow the generation of particular cell types for the treatment of degenerative disease.