ABCG2 and cancer: In the case of the immunization-challenged group compared to the mock group, the differential metabolites in the KEGG signaling pathway were mainly enriched in ABC transporters, Choline metabolism in cancer, Glycerophospholipid metabolism, Metabolic pathways, Biosynthesis of amino acids, Thyroid hormone synthesis, Glycerophospholipid metabolism, Arachidonic acid metabolism, Linoleic acid metabolism, and alpha−Linolenic acid metabolism.