We found that positive ABCB1 activity was associated with high expression of CD34, specifically, in ABCB1 positive AML 85% of blasts express CD34 compared to ABCB1 negative AML in which only 12% of blasts express CD34 (p < 0.001; Table 1, Figure 1D). Here, CD34 is linked to acute myeloid leukemia.