On day 36 after the transplant, the percentage of HL-60 cells in the leukocytes collected from spleen and bone marrow was analyzed with flow cytometry, which was 57.3% and 92.7% in the spleen and bone marrow respectively, detected by human CD33 expression, confirming the leukemia burden was formed and proving the effect of E5 in anti-acute myelocytic leukemia as well. Here, CD33 is linked to leukemia.