XBP1 and B-cell chronic lymphocytic leukemia: In that respect, TCL1A-mediated B-CLL development begins by an increased XBP-1 and AID expression, evolving in 8 months to malignant cells with increased IRF4 and BLIMP-1 expression, associated with reduced Akt expression, which may indicate other ways for TCL1A than Akt coactivation in CLL development (cf. Figure 1) [114].