More on Nanog and the creation of stem cells on demand through dedifferentiation via EurekAlert: in culture, embryonic stem [ES] cells tend "to lose stemness and evolve into muscle cell precursors, most likely goaded by a muscle differentiation factor known as BMP. ... When BMP turns ES cells into muscle it activates a protein called Smad1, a DNA-binding protein that, in opposition to Nanog, switches on genes responsible for muscle cell fate. Smad1 can only do this when assisted by generic factors known as co-activators, which stimulate gene expression. ... Nanog actually binds to Smad1 protein and interferes with its ability to recruit those obligatory coactivators, thereby rendering Smad1 powerless to initiate muscle gene expression. With Smad1 out of the game and Nanog in full control, cells revert to their forever-young state. ... in suitable conditions, differentiated cells are still capable of producing stem cells as descendants. The molecular mechanisms that we identified here might be used to regenerate stem cells from differentiated cells."