In this article, we showed that iPSC lines derived from different somatic cell populations can be grown in a hESC-based protocol using a xenogenic-free defined medium and differentiation protocol optimized for hESCs. Using this 4-step scalable process (propagation of hESCs → generation of NSCs → induction of dopaminergic precursors → maturation of dopaminergic neurons), we tested two iPSC lines derived from different somatic cells (adult fibroblast and mesenchymal stem cell) and generated NSCs and subsequently dopaminergic neurons from them. We showed that each of the manufacturing steps could be performed using xeno-free defined conditions in iPSCs similar to hESCs. Neurons generated by this process appeared to be authentic A9 dopaminergic neurons as assessed by in vitro (marker expression) and in vivo (transplantation in PD animal model) assays. This observation was not entirely unexpected as it has been observed that the reprogramming factors are not needed forever. Indeed, once the cells are reprogrammed, they express endogenous pluripotency genes and silence the exogenous ones. Thus, like ESCs or other pluripotent cells, iPSCs should readily differentiate into appropriate lineages and respond in a
