Genetic studies, first done in model eukaryotes and more recently in mammals, have revealed thathomology-directed DNA repair (HDR) plays a critical role in the elimination of DNA double-strandbreaks and in the preservation of stressed or injured DNA replication forks. HDR is reliant on the tumorsuppressors BRCA1-BARD1, BRCA2, and PALB2, mutations in which cause breast, ovarian, and othercancers.
