Induced pluripotent stem cells: what lies beyond the paradigm shift

The discovery that somatic cells can be reprogrammed to become induced pluripotent stem (iPS) cells has ushered in a new and exciting era in regenerative medicine. Since the seminal discovery of somatic cell reprogramming by Takahashi and Yamanaka in 2006, there has been remarkable progress in the characterization of PS cells and the protocols used to generate them. The new information generated during the past year alone has vastly expanded our understanding of these cells. Accordingly, this review provides a basic overview of the different strategies used to generate PS cells and focuses on recent developments in the field of PS cells. In the final section, we discuss three broad, unanswered questions related to somatic cell reprogramming, which are just starting to be addressed.