Zfx: at the crossroads of survival and self-renewal.

As the molecular mechanisms that govern stem cell fate are beginning to be unraveled, Galan-Caridad et al. (2007) report in this issue of Cell a common role for the transcription factor Zfx in the self-renewal/maintenance of both embryonic stem cells and hematopoietic stem cells. Their work suggests that a regulator of self-renewal can be shared between two different cell types.