IRF4 and diffuse large B-cell lymphoma: Accordingly, enforced expression of NIK and BCL6 in the GC, as obtained by conditional mutagenesis in the IμHABcl6;NikstopFL;Cγ1-Cre mouse model, caused GC hyperplasia with blockade of terminal differentiation and development of IRF4-positive DLBCL (168).