In addition, the top 5 significantly enriched KEGG pathways for PCOS vs POF group metabolites included protein digestion and absorption pathways, ABC transporter-dependent pathways, central carbon metabolism pathways in cancer, aminoacyl-tRNA biosynthesis pathway, and prostate cancer pathways; these pathways were identified using the MetPA tool (Figure 5d and Table 2). Here, ABCG2 is linked to polycystic ovary syndrome.