How signaling promotes stem cell survival: trophoblast stem cells and Shp2.

Trophoblast stem (TS) cells require FGF4 for self-renewal and to prevent differentiation. In this issue of Developmental Cell, Yang and colleagues show that the tyrosine phosphatase Shp2 prevents apoptosis in TS cells, by activation of Erk and subsequent phosphorylation and destabilization of the pro-apoptotic protein Bim. These studies provide a novel link between FGF/Erk signaling and cell survival that may be relevant to other stem and progenitor cell niches.