A bone marrow biopsy was performed, which revealed a donor derived acute myeloid leukemia (AML), with 22% blasts showing an immature myeloid phenotype by flow cytometry (CD13+, CD34+, HLA-DR+, CD4dim+, CD64dim+, and CD33 partial dim+), negative for CD10 and CD19, both of which had been expressed in the prior B-ALL. The gene discussed is CD33; the disease is acute myeloid leukemia.