Flow cytometric detection of MRD after induction chemotherapy in the peripheral blood of an AML patient led by the patient's LAIP, which included CD25. In the scattergram, a gate (P1) is set around cells with low forward scatter (FSC) and side scatter (SSC), reflecting small to intermediate size and low granularity, respectively. In the blast gate, cells within P1 with high CD34 and high CD13 expression are selected away (P2) from CD34⁻CD13⁻ cells (red dots), representing predominantly lymphocytes. Some CD34⁻CD13⁺ cells are monocytes caught in P1. In the blast cell characterization contour plot, MRD is detected within the CD34⁺CD13⁺ gate based on the expression of CD25 and intermediate CD45 staining (green cluster). These cells with the patient's LAIP features (CD34⁺CD13⁺CD45^WEAKCD25⁺) account for 0.003% of all nucleated cells, a common denominator for MRD definition. The blue CD25⁻ cluster represents normal myeloid precursor cells (CD34⁺CD13⁺CD45^WEAKCD25⁻) caught in P2.