Although in vitro data using the K562 cell line has suggested that MRP1 only plays a minor role in the efflux of imatinib and dasatinib, it would be interesting to investigate whether other TKIs are substrates and whether MRP1 is differentially expressed in chronic phase CML patients [61]. Here, ABCC1 is linked to chronic myelogenous leukemia, BCR-ABL1 positive.