IL27 and B-cell chronic lymphocytic leukemia: Using ex vivo PBMC cultures from treatment-naive CLL patients, we demonstrated that IL-27 stimulation induces a statistically significant increase in TIM-3 expression on CD8+ T lymphocytes (from 2.18 ± 0.32% to 3.09 ± 0.49%, p = 0.009) and elevates total TIM-3+ lymphocyte frequencies (from 5.77 ± 0.85% to 7.54 ± 1.27%, p = 0.011).