This has been shown in artificial systems10,21, and in yeast and human cells depleted of R-loop suppressor factors such as THO, Sin3A, Fanconi Anemia, Sen1/SETX, the UAP56/DDX39B helicase, or the bromodomain chromatin factor BRD45,11,12,22–24. This evidence concerns the gene SETX and Fanconi anemia.