By contrast, interesting preliminary results in terms of response rate have been obtained when checkpoint inhibitors were administered, alone or in association with ibrutinib, to CLL patients developing a Richter’s transformation to diffuse large B-cell lymphoma, and particularly to those patients showing a higher expression of PD-L1 and PD-1 in the tumor microenvironment (285, 289). This evidence concerns the gene CD274 and B-cell chronic lymphocytic leukemia.