ABCG2 and uterine carcinoma: The uterine carcinoma UXF1138L xenograft used in this study is overall resistant to standard chemotherapy including drugs that are substrates of Pgp and BCRP such as doxorubicin and mitoxantrone (Fiebig and Burger, 2001); only Taxol has single-agent activity and tumours inevitably re-grow after treatment (Figure 5B).