GZMK and B-cell chronic lymphocytic leukemia: The increased differentiation of EBV-specific CD8+ T cells in CLL patients is accompanied by trends towards higher expression of granzyme B, lower expression of granzyme K, and a significant increase in expression of the fractalkine receptor CX3CR1 (Fig. 2C–E, global CD8+ T cells in Supplemental Fig. 3D–F).