However, OT1 and OT2 recipient mice also exhibited robust PD1 expression in non-CLL-specific Vb5pos T cells, similar to the extent observed in CD4/CD8 T cells from WT recipients (mean OT2: preTx 2.3%, postTx 10.8%, p = 0.0049, n = 16; mean OT1: preTx 1%, postTx 13.5%, p = 0.0022, n = 16) (Figure 1B,C). Here, CD4 is linked to B-cell chronic lymphocytic leukemia.