Expression of BLyS in NHL tumors. Immunohistochemical analysis of BLyS expression in (A) DLC, (B) B-CLL/SLL, (C) follicular, (D) mantle cell, and (E) marginal zone NHL specimens (n = 5 for each histologic subtype) was performed with the anti-BLyS mAb from Chemicon as described in “Patients, materials, and methods.” An isotype control was done for each specimen and a representative example is shown in panel F. Original magnification × 400.