BCL10 protein expression in normal NK cells and NL and the NF-κB expression in NL. (A) A moderate immunoreactivity was detected only in the cytoplasm of NK cells. (B) The NL tumor cells from case 29 showed strong BCL10 expression in both the nucleus and cytoplasm. (C) Cytoplasmic BCL10 staining and aberrant nuclear staining of BCL10 on the tumor cells in case 28. (D) Nuclear localization of NF-κB was prominent in the same case in addition to the cytoplasmic staining, indicative of NF-κB activation in the tumor cells. (E) Cytoplasmic staining of BCL10 was present in the tumor cells of case 22. (F) Cytoplasmic localization of NF-κB is shown in the same case. Immunoperoxidase staining: original magnifications of panels A-F and inset in panel B are × 400 and × 1000, respectively.