CD33 and acute myeloid leukemia: Moreover, in recipients of CD3−CD19− MNCs >90% of all engrafted human leukocytes were of the myeloid lineage (CD33+) and the majority of engrafted human myeloid cells showed the same phenotype compared to diseased AML #7–9 before transplantation, suggesting that predominantly diseased AML cells engrafted and expanded.