In Ewing sarcoma cells, the fusion of EWS RNA binding protein 1 (EWSR1) and Friend leukemia integration 1 transcription factor (FLI1) EWS-FLI1 can increase transcription, replication stress and R-loop formation and lead to blocked BRCA1-mediated repair after DNA damage [106]. The gene discussed is EWSR1; the disease is Ewing sarcoma.