Furthermore, Xia et al. reported significantly elevated OGG1 protein expression in granulosa cells from PCOS patients, and also measured higher OGG1-related signal levels in serum and follicular fluid using ELISA, although the precise extracellular form and functional relevance of OGG1 in these fluids remains to be clarified [96]. This evidence concerns the gene OGG1 and polycystic ovary syndrome.