Distribution of rhodamine (A and C) or daunorubicin (B and D) content in normal CD34⁺ cells or AML blasts after the rhodamine/daunorubicin efflux assay (1). The 25% most rhodamine/daunorubicin dull cells were sorted and triggered to proliferate by exposure to HGFs for 48 hours (2). After proliferation, induction cellular rhodamine/daunorubicin was higher compared with the sorted rhodamine/daunorubicin dull cells.