In an analysis of the expression of the exhaustion markers PD-1, TIM3 and LAG3, we identified that the expression of all three decreased on CD4+ and CD8+ T cells from untreated patients with CLL after three days of culture in the presence of ibrutinib, but not acalabrutinib or zanubrutinib. Here, CD4 is linked to B-cell chronic lymphocytic leukemia.