Since the PD1/PD-L1 axis was already shown to contribute to T cells dysregulations in both human and mouse models of CLL, we used MI-2 therapy as a pretreatment for checkpoint blockade with anti-PD-L1 antibody in immunocompetent TCL1-leukemia bearing mice (6, 29). Here, PDCD1 is linked to B-cell chronic lymphocytic leukemia.