TOP1 and colorectal carcinoma: To clarify whether HDGF promotes HR-mediated DNA repair in CRC cells, we induced DNA DSBs in HCT116 WT and HCT116 HDGF-KO cells, as well as HT29 WT and HT29 HDGF-KO cells, using the DNA topoisomerase I inhibitor camptothecin (CPT).