Due to the increased expression of Lmo2 in DLBCL (Natkunam et al, 2007; Cubedo et al, 2012), we therefore next crossed conditional Rosa26‐Lmo2 mice with the Aid‐Cre strain, which expresses Cre recombinase in germinal center (GC) B cells (Crouch et al, 2007). Here, LMO2 is linked to diffuse large B-cell lymphoma.