Primed to perish: heightened mitochondrial priming explains hESC apoptosis sensitivity.

Human embryonic stem cells (hESCs) are hypersensitive to apoptotic stimuli, though the underlying mechanisms are poorly characterized. In this issue of Cell Stem Cell, Liu et al. (2013) report that mitochondria of human ESCs exist in an apoptosis-prone state, ready to act as cellular executioners upon detecting DNA damage.