Wnt + BMP = stem cell

Stem cell fate is determined by growth factors. But on page 309, Kléber et al. show that the right combination of growth factors can also keep cells from committing to a differentiated fate. Neural crest stem cells (NCSCs), they find, are maintained by the dual punch of Wnt and BMP.NCSCs have the potential to become many different cell types. For example, Wnt exposure of NCSCs results in sensory neurons, BMP exposure results in autonomic neurons, TGFβ exposure results in smooth muscle, and NRG1 exposure results in glia. Most NCSCs see Wnt as they leave the neural tube and start to migrate throughout the developing embryo. Yet not all become sensory neurons. The new results indicate that some escape because BMP is present to block Wnt's differentiation activity, as has also been...