XRCC1 and polycystic ovary syndrome: The expression of genes related to DNA repair, including inhibitor of kappa light polypeptide gene enhancer in B-cells, kinase beta, ligase I, DNA, ATP-dependent, and X-ray repair complementing defective repair in Chinese hamster cells 1 (XRCC1), was higher in PCOS oocytes than in normal oocytes at early phases, but the expression of these genes was normal at the MII phase (Fig. 5D).