BCL2 and Splenomegaly: AicdaCre/wt;Myd88p.L252P/wt;Cd79bp.Y195H/wt;Rosa26LSL.BCL2.IRES.GFP/wt;Prdm1fl/fl animals developed splenomegaly and B cells in these animals displayed immune-phenotypes consistent with dark zone GC B cells and memory B cells (65). A further analysis, using bone marrow chimeras, revealed that 5 of 8 AicdaCre/wt;Myd88p.L252P/wt;Cd79bp.Y195H/wt;Rosa26LSL.BCL2.IRES.GFP/wt;Prdm1fl/fl animals displayed disrupted splenic architecture due to a proliferation of large atypical lymphoid cells that morphologically resembled DLBCL (65).