Figure 1. Rejuvenation by cell reprogramming of fibroblasts from healthy centenarian individuals. In culture, fibroblasts from old individuals display a typical transcriptional signature, different of that from young counterparts as well as shortened telomeres, reduced population doubling (PD) potential, dysfunctional mitochondria and higher levels of oxidative stress. When cells were reprogrammed to iPS with a 6-factor cocktail the above alterations were fully reversed. Then iPS cells were differentiated back to fibroblasts by culture in the presence of an appropriate set of differentiation factors. In the resulting cells, all of the above variables had levels typical of fibroblasts taken from young individuals. See  for further details.