ABCG2 and cancer: The most significant KEGG for upregulated genes involved in pathways in cancer were the PI3K-Akt signaling pathway; axon guidance; focal adhesion; calcium signaling pathway; RAS signaling pathway; cAMP signaling pathway; Wnt signaling pathway; cGMP-PKG signaling pathway; protein digestion and absorption; oxytocin signaling pathway; hippo signaling pathway; insulin secretion; glutamatergic synapse; APLN signaling pathway; ECM–receptor interaction; TGF-beta signaling pathway; circadian entrainment; gastric acid secretion; and ABC transporters (Figure 1E).