It's been a while since nanog was discussed here; it's one of the genes associated with early efforts to reprogram somatic cells into stem cells and seems to be important in the activity of embryonic stem cells. Here researchers are investigating the reversal of stem cell aging: "Although the therapeutic potential of mesenchymal stem cells (MSC) is widely accepted, loss of cell function due to donor aging or culture senescence are major limiting factors hampering their clinical application. Our laboratory recently showed that MSC originating from older donors suffer from limited proliferative capacity and significantly reduced myogenic differentiation potential. This is a major concern, as the patients most likely to suffer from cardiovascular disease are elderly. Here we tested the hypothesis that a single pluripotency associated transcription factor, namely Nanog, may reverse the proliferation and differentiation potential of BM-MSC from adult donors. Microarray analysis showed that [expressing Nanog] markedly upregulated genes involved in cell cycle, DNA replication and DNA damage repair and enhanced the proliferation rate and clonogenic capacity of [adult] BM-MSC. Notably, Nanog reversed the myogenic differentiation potential and restored the contractile function of [adult] BM-MSC to a similar level as that of neonatal BM-MSC. ... Overall, our results suggest that Nanog may be used to overcome the effects of organismal aging on BM-MSC, thereby increasing the potential of MSC from aged donors for cellular therapy and tissue regeneration."