Moreover, the top 5 significantly enriched KEGG pathways for POF vs. CTRL group metabolites included ABC transporter-dependent pathways, protein digestion and absorption pathways, central carbon metabolism pathways in cancer, mineral absorption pathways, and cortisol synthesis and secretion pathways; these pathways were identified using the MetPA tool (Figure 4d and Table 2). The gene discussed is ABCG2; the disease is cancer.