Consistent with this possibility, E2F1 depletion did not reduce BRCA1 expression in ovarian cancer cell lines (Fig. 4e; Supplementary Fig. 6a) or in freshly isolated HGSOC tumors from two different mouse PDX models (Supplementary Fig. 6b, c) using primers that are specific for human BRCA1 (Supplementary Fig. 6c), thus demonstrating that E2F1 does not play a major role in BRCA1 transactivation in HGSOC. Here, E2F1 is linked to ovarian carcinoma.