CD4 and B-cell chronic lymphocytic leukemia: The T-cell compartment in CLL patients is dysfunctional, showing in particular: i) an increased expression of inhibitory receptors and a defective immune synapse formation upon contact with CLL cells (8); ii) skewing of T-cell subsets from naïve to memory T cells and an increase in the number of circulating T cells both in the CD4+ and the CD8+ compartments (9); iii) a higher expression of exhaustion markers (10); iv) within the CD4+ cells, a T-helper (Th)2/Th1 ratio imbalance with an aberrant recruitment of a Th2-dominant response (11, 12).