BCL2 and diffuse large B-cell lymphoma: Richter transformation was characterized in these animals by the occurrence of large blastoid cells in the splenic infiltrates, reminiscent of bona fide DLBCL clones that develop in animals that co-express oncogenic Myd88L252P and BCL2 in a B cell-specific manner22, as well as those developing in Eμ:TCL1;Cd19Cre/wt;AktC mice (Fig. 2b).