CRISPR: Stressed about p53?

Two recent reports show that, in some contexts, CRISPR-mediated genome editing can lead to a p53-mediated stress response and cell-cycle arrest. These findings may help to explain why CRISPR-mediated genetic manipulation in different cell types leads to dissimilar outcomes, and highlights the need for a better understanding of the factors that influence effective genome editing in vitro and in vivo.