ABCG2 and acute promyelocytic leukemia: As cisplatin (CDDP) and mitoxantrone (MTX) are possible substrates of ABC transporters, Jendželovská et al. evaluated the action of 24 h of hypericin treatment on the toxic effects of CDDP and MTX in HL-60 promyelocytic leukemia cells and ABCG2-over-expressing the cBCRP subclone [89].