ABCG2 and cancer: Previous studies showed that the PI3K/AKT pathway enhanced the biological basis of cancer by effectively expressing ABC transporters containing p-glycoprotein (P-gp, ABCB1), multidrug resistance-associated protein 1 (MRP1, ABCC1), and breast cancer resistance protein (BCRP, ABCG2), whose activation may reduce the response to chemotherapy drugs and enhance the drug efflux29,30.