ABCG2 and cancer: Interestingly, thirteen core ADME genes (ABCB1, ABCC2, ABCG2, CYP2D6, CYP2E1, CYP3A5, DPYD, GSTP1, GSTT1, NAT1, SLC15A2, SULT1A1, TPMT) were expressed in all 21 cancer types.