ATP-binding cassette, sub-family G (WHITE), member 2 ATP-binding cassette sub-family G member 2 BCRP1 ATP-binding cassette protein G2 Bcrp ATP-binding cassette, subfamily G (WHITE), member 2 ATP binding cassette subfamily G member 2 (Junior blood group) breast cancer resistance protein 1 homolog broad substrate specificity ATP-binding cassette transporter ABCG2 urate exporter