ABSTRACT
Around the turn of the millennium, there was a veritable flurry of publications and general excitement in the stem cell world around the possibility that adult stem cells with supposedly restricted potential could in fact contribute to a much wider range of tissues than expected. Such presumed capacity, which could be considered trans differentiation, was put under a banner of stem cell “plasticity.” Differentiation can result in cells that have characteristics of fetal tissues, as is seen, for example, with hepatocytes and cardiomyocytes, so that is appealing to have the prospect of reprogramming directly to an adult phenotype without the requirement for an iPS cell stage. Aside from the advantage of ensuring generation of a functional adult cell, direct lineage reprogramming avoids potential problems arising from the potentially tumorigenic nature of pluripotent stem cells; however, the advantage of potentially indefinite expansion is lost.
