Research is shedding light on the structural basis of Ku-mediated activation of WRN exonuclease activity. The WRN protein, also known as the Werner Syndrome Helicase-Nuclease, appears to play a role in DNA double-strand break repair and telomeric recombination events. The specifics of its function and interaction with other proteins, such as those involved in non-homologous end-joining, are being explored.