Tetramer analyses in PB and BM. (A) Representative flow cytometry analysis of WT1 tetramers in patient no. 1. Lymphocytes were gated on CD3⁺ and CD8⁺ T cells, whereas CD4⁺, CD13⁺, CD19⁺, CD33⁺, and CD34⁺ cells were excluded to avoid nonspecific tetramer staining. WT1-specific T cells were calculated as CD8⁺ tetramer⁺ T cells. (B) WT1-tetramer CD3⁺CD8⁺T cells in PB and BM at baseline and during the course of vaccination. Patients with high and low blasts in BM at baseline are shown separately.