Since several reports describe the increased expression of PD-1 and CTLA-4 on T cells in CLL, and a PD-1/PD-L1 blockade induced therapeutic responses and recovery of T-cell function in a mouse model of CLL, blocking these receptors with monoclonal antibodies seemed a promising strategy [30,31,55,56]. Here, CTLA4 is linked to B-cell chronic lymphocytic leukemia.