Fig. 3

Programmed death receptor 1 (PD-1) expression on CD4⁺ and CD8⁺ T cells in patients with CML receiving TKIs, either alone or in combination with IFN-α, and in healthy controls. PD-1 expression on CD4⁺ (a, b) and CD8⁺ T cells (c) from CML patients stratified by type of TKI used (imatinib or 2nd generation TKI). The p values in the figure reflect statistically significant differences among study groups