Further to explore the molecular pathogenesis of PCOS, proteomics was performed on follicular fluid samples to identify 144 DEPs between the healthy individuals and PCOS patients, which enriched in TNF-α signaling via NF-κB, VEGF signaling pathway, PPAR signaling pathway, IL-2-STAT5 signaling, epithelial mesenchymal transition (EMT), bile acid metabolism, mTORC1 signaling, as well as oxidative phosphorylation. This evidence concerns the gene VEGFA and polycystic ovary syndrome.