Here, we used a network-based strategy to identify drugs that block hubs of fluoroquinolone antibiotic-induced mutagenesis. We identify a U.S. Food and Drug Administration– and European Medicines Agency–approved drug, dequalinium chloride (DEQ), that inhibits activation of the Escherichia coli general stress response, which promotes ciprofloxacin-induced (stress-induced) mutagenic DNA break repair. We uncover the step in […]