CLL cells disable CTLs through interactions mediated by immunosuppressive surface ligands such as the PD-1 ligand (PD-L1) which, by activating the inhibitory cognate receptors on CTLs, hamper IS formation and polarized lytic granule secretion of into the synaptic cleft to allow for selective tumor cell killing [7, 12]. Here, CD274 is linked to B-cell chronic lymphocytic leukemia.