CD79B and B-cell chronic lymphocytic leukemia: In addition, CLL cells of IgβΔc/Δc;Eμ-TCL1 mice were not susceptible to anti-Igβ antibody treatment compared to CLL cells that originated from conventional Eμ-TCL1 mice (Figure 3) indicating that the CLL cells survive independently of Igβ-tail signaling.