Attenuation of RNA polymerase II pausing mitigates BRCA1-associated R-loop accumulation and tumorigenesis

The vast majority of BRCA1-driven breast cancers derive from luminal progenitor cells but the mechanisms of this lineage specificity are unclear. Here the authors show that dangerous accumulation of DNA-RNA hybrid structures due to RNA polymerase II pausing, occurs specifically in luminal epithelial cells.