Adult cell plasticity in vivo: de-differentiation and transdifferentiation are back in style

Biologists have long been intrigued by the possibility that cells can change identity, a phenomenon known as cellular plasticity. The discovery that terminally differentiated cells can be coaxed experimentally to become pluripotent has invigorated the field, and recent studies have demonstrated that changes in cell identity are not limited to the laboratory. Specifically, certain adult cells retain the capacity to de-differentiate or trans-differentiate under physiological conditions as part of an organ's normal injury response. Recent studies have highlighted the extent to which cell plasticity contributes to tissue homeostasis, findings that have implications for cell-based therapy