BCA-1 mRNA expression in PCNSL.

In situ hybridization confirms BCA-1 expression in brain biopsy specimen from a patient with PCNSL. Antisense (A) and sense (C) hybridizations are shown (hematoxylin counterstain, original magnification × 40). (B) Vascular endothelium does not appear to synthesize BCA-1 because BCA-1 mRNA is localized solely to B lymphocytes (hematoxylin counterstain, original magnification × 200). (D) In human tonsil, BCA-1 mRNA is present in the lymphoid follicles (hematoxylin counterstain, original magnification × 200).