In a recent genome-wide siRNA screen in ovarian cancer cells treated without or with CX-5461, a number of genes known to be important in HR DNA repair and other DNA repair pathways were identified to be synthetic lethal with CX-5461.295 The loss of DNA topoisomerase I (TOP1) was shown to cooperate with CX-5461 in inhibiting cell proliferation. This evidence concerns the gene TOP1 and ovarian cancer.