Frequency of MDSCs in CML patients at diagnosis, pre-MMR, MMR, MR^4.5, TFR, and in HD. (A) (i) HLA-DR⁻LIN⁻CD11b⁺CD33⁺ MDSC gating. (ii) MDSCs as a percentage of PBMCs. (iii) Representative patient (of 8 patient samples) showing the absolute number of MDSCs per microliter (blue) against BCR-ABL1 (red) over time. (B) (i) CD66b⁺CD15⁺ Granulocytic (Gr)-MDSC gating (left) and percent Gr-MDSC (right) in CML patients. (ii) CD66b⁻CD14⁺ Mo-MDSC gating (left) and percent Mo-MDSC (right) in CML patients. Bars denote the median. MDSCs were derived from side scatter vs FSC gated bulk PBMCs, with doublet exclusion (FSC-A vs FSC-H) and dead cell discrimination (dead cell stain⁻). ***P ≤ .001; **P ≤ .01; *P ≤ .05.