Fig. 2.

Challenges to clinical translation. Numerous challenges face the clinical application of cell identity reprogramming technologies. In vitro generation of neurons requires a large population of patient-specific source cells for reprogramming and transplantation. Alternatively, in vivo reprogramming strategies typically target large glial cell populations for neuronal induction. The refinement of reprogramming factor delivery, genetic correction of disease-causative mutations, and characterization of induced neurons will be essential to the clinical evaluation of these technologies.