BRCA2 and cancer: Nuclear R-loop accumulation detected by the S9.6 antibody specific to R-loop structures (Bhatia et al., 2014, Ginno et al., 2012) increases following BRCA2 inactivation by small interfering RNA (siRNA)-mediated depletion in HeLa Kyoto cells (Figures 1A and S1A) or by bi-allelic cancer-associated truncating mutations (BRCA27691insAT/ 9000insA) in the patient-derived EUFA423 fibroblast cell line (Howlett et al., 2002) (Figures 1B and S1C).