Cells were then stained using antibodies to CD45 and CD73 to identify the AML and stromal cells prior to the addition of Annexin V. Strikingly, in both OCI-AML3 and KG1a cells, the LC50 (cytarabine dose that kills 50% of cells) was not achieved in the adhered AML cells even at the highest dose of 10 μM, indicating a strong chemotherapy resistance effect created by adhesion in the BMAS: adhered LC50 > 10 μM. This evidence concerns the gene NT5E and acute myeloid leukemia.