Figure 4. Treatment with BTK inhibitors significantly reduces the frequency of T cells expressing intracellular CTLA-4.

Percentages of cells positive for intracellular CTLA-4 expression among total CD4⁺ T cells, CD45RA^– CD4⁺ T cells, and CD45RA⁺ CD4⁺ T cells from CLL patients before and during treatment with (A) ibrutinib (n = 18) and (B) acalabrutinib (n = 9). Differences were assessed using linear mixed-effects models. Data for CD8⁺ T cells are shown in Supplemental Figure 4.