This PD-1/PD-L1 increase is discordant in the literature, as some authors report no (91, 92) or feeble (92, 95) expression of PD-L1/PD-L2 on circulating CLL cells/lymph node SLL (Table 1A). This evidence concerns the gene PDCD1LG2 and B-cell chronic lymphocytic leukemia.