PD-1 expression on T-cells, T-regs and NK cells in patients with CML and in HD. PD-1 expression on T cells was not different between the MolR, TFR, or healthy donor (HD) groups either (A) as a percentage of T cells or (B) absolute counts. Similarly, there were no differences observed in (C) percentage of CD4⁺T cells, (D) absolute counts of PD-1⁺CD4⁺T cells, (E) percentage of CD8⁺T cells or (F) absolute counts of PD-1⁺CD8⁺T cells. (G) PD-1 expression as a percentage of T-regs was not different between the groups. (H) However, the absolute count of PD-1⁺T-regs was significantly higher in the patients in MolR group than in those in the TFR group. There was no difference in PD-1 expression on NK cells either (I) as a percentage of NK cells or (J) absolute counts. The Mann-Whitney test was used to compare 2 groups, whereas multiple comparisons were made using the Kruskal-Wallis test; alpha was set at 0.05 (adjusted for multiple comparisons).