IRF4 and diffuse large B-cell lymphoma: DLBCL deriving from B cells that exit from the GC or from post-GC B cells (activated B-cell-like [ABC] subtype), are characterized by dependence on BCR and NFκB signaling, IRF4/MUM1 expression [97] and enrichment for BCR pathway mutations (e.g., MYD88, CD79B, PIM1) and PRDM1/BLIMP1 mutations/deletions [95].