TPX2 joins 53BP1 to maintain DNA repair and fork stability.

In this issue, Byrum et al. (2019. J. Cell Biol. https://doi.org/10.1083/jcb.201803003) surprisingly identify an interaction between 53BP1 and the mitotic regulators TPX2 and Aurora A that lead them to novel mechanistic insights about DNA double-stranded break repair regulation and a new fork protection pathway during replication stress.