TOX and B-cell chronic lymphocytic leukemia: However, neither significant shifts in the expression of the T-cell exhaustion-associated transcription factor, TOX, nor distribution of CLL-suppressed CD8+ T-cells into progenitor-like (PD1lo/TIM3−) and terminally (PD1hi/TIM3+) exhausted categories [28] were witnessed with any BA treatment (Figure 4D,E).