ABCG2 and leukemia: Early pre-clinical investigation of the anticancer potential of ITZ focused on a potential role as a potentiator for chemotherapeutic drugs, particularly as a possible agent to reverse multi-drug resistance (MDR).Examples include in vitro studies on the reversal of MDR in a murine P388 leukaemia cell line resistant to daunorubicin [14], human leukaemia cell lines resistant to Adriamycin and etoposide [15] and in human breast cancer resistance protein (BCRP) expressing human embryonic kidney (HEK) cells resistant to topotecan [16].