CTLA4 and B-cell chronic lymphocytic leukemia: These findings are in line with recent reports demonstrating that CD8+ T cells from patients with chronic lymphocytic leukemia exhibit features of T cell exhaustion, i.e., lower proliferative and cytotoxic capacity and increased expression of inhibitory receptors (e.g., CTLA-4, TIGIT, Lag3, PD-1), suggesting both CLL and T cell-specific changes leading to decreased ability to eliminate malignant cells [55–58].