In a paper published in PLoS One this week, a team led by researchers at the University of Pittsburgh shows that human embryonic and induced pluripotent stem cells show similar responses to DNA damage. Specifically, the team writes, "iPS cells [temporarily] arrest cell cycle progression in the G2 phase of the cell cycle, displaying a lack of the G1/S cell cycle arrest similar to human ES cells" in response γ-irradiation-induced apoptosis.