JUNB and TRAF1 expression in normal lymphoid tissues. Serial sections of tonsillar GC were stained with JUNB, CD20, TRAF1, and Ki67 (A,C; magnification 10×). The right panels are enlargements from the light zone (magnification 80×). (A,B) Cells displaying nuclear staining for JUNB (blue) localize in the light zone (LZ) and show costaining for CD20 (brown). (C,D) Ki67 staining (brown) identifies the GC DZ (Ki67^high) and LZ. GC cells expressing cytoplasmic TRAF1 (blue) are located mainly in the light zone.