Indeed, silibinin, in a dose-dependent manner with applying no cytotoxic effects, inhibited cell proliferation and reduced mRNA expression levels of some transporter genes, e.g., MDR1, MRP3, MRP2, MRP1, MRP5, MRP4, ABCG2, ABCB11, MRP6 and MRP7 in chronic myelogenous leukemia (CML) in vitro models, K562 and KCL22 cell lines [35]. The gene discussed is ABCG2; the disease is chronic myelogenous leukemia, BCR-ABL1 positive.