In patient #5, the previous BCP-ALL cells (CD19+iCD79a+CD10-/+CD34-CD45dim, 38.6% in BM prior to blinatumomab) had been completely replaced by myeloid leukemic cells (CD19-iCD79a-iCD22-CD33+CD117+CD34-CD14-CD11c+) by Day 27 of the blinatumomab course. This evidence concerns the gene CD33 and acute lymphoblastic leukemia.