Tinkering with transcription factors uncovers plasticity of somatic cells.

The advent of induced pluripotent stem cells (iPSCs) has brought the goal of using patient-derived cells for tissue repair closer to reality. However, the mechanisms involved in reprogramming to a pluripotent state are still not clear. It is understood that reprogramming to pluripotency involves epigenetic remodeling and the reactivation of "core" pluripotency factors. However, little is known about the mechanisms involved in overcoming senescence while avoiding oncogenesis, the maintenance of self-renewal, and the regulation of the balance between pluripotency and differentiation. Here, we review recent advances in reprogramming technology and what is currently known about the mechanism of reprogramming to pluripotency. Work with patient-derived iPSCs is already providing new insights into the cellular and molecular mechanisms involved in human disease. Further advances in reprogramming technology should result in efficient methods to reprogram patient-derived cells into iPSCs for use in regenerative medicine.