Cd19+/Cd5+ “CLL-like” cell populations were observed in both Eμ-PRMT5 and Eμ-TCL1 mice but did not comprise the entire B-cell compartment, yet clustered in regions with the highest cell density within each model (Fig. 3a, b). The gene discussed is PRMT5; the disease is B-cell chronic lymphocytic leukemia.