Exploiting deficiencies in tumor cells’ inability to repair damage to their DNA has been one of the most successful endeavors of oncology research in recent memory. There are four approved PARP inhibitors to treat certain types of breast, ovarian, pancreatic and prostate cancers. Multiple other synthetic lethal combinations that might push repair-deficient tumors into cell death are being investigated. In the July 29, 2022, issue of Science, researchers at Yale University have described another approach to turning DNA repair defect against itself. Startup Modifi Biosciences Inc. is now on course to translate that work.