CCL4 and polycystic ovary syndrome: In this study, FF MIP-1β was found to be associated with the number of D3 good-quality embryos, the rate of D3 good-quality embryos and the good-quality blastocyst rate, which may be a non-invasive indicator to assess embryo quality and viability in normal-BMI PCOS patients undergoing IVF treatment, and can be combined with the morphology score to optimize embryo selection to obtain the best embryos for transfer, which may lead to an increase in pregnancy and live birth rates and a decrease in miscarriage rates.