BAFF, BAFF-R, and p52 staining. A–C: BAFF staining. D–F: BAFF-R staining. G–I: p52 staining. A: Tonsil control. High expression in GC cells, weak expression in mantle cells, and heterogeneous staining in the interfollicular zone. B: Positive staining. C: Weak staining. D: Tonsil control. High expression in mantle cells and heterogeneous staining in GC cells. E: Positive staining. F: Negative staining. G: Tonsil control. Nuclear (arrow) and cytoplasmic staining in GC cells. H: Positive staining, nuclear localization (arrow). I: Negative staining, cytoplasmic localization (arrow).