GDF9 and polycystic ovary syndrome: Our results displayed a significant increase in the expressionof GDF-9 in the unfertilized mature oocytes ofPCOS patients after administration of NAC comparedto MET, indicating that NAC, as an anti-oxidant/antiapoptoticagent, could enhance the expression of GDF-9through inhibiting the activity of NF-kB and AP-1 transcriptionfactors, therefore affecting the activity of MAPkinasesignaling and related genes expression (33), whichmay be able to alleviate PCOS follicular disorders andprevent follicular developmental detention and atresia.