Immunohistochemical staining of VEGF protein.

The presence of VEGF protein in CLL nodes (n = 3; CLL17 shown) and spleen (n = 2; CLL20 shown), together with corresponding normal tissues (n = 3), was examined using anti-VEGF antibody staining. Infiltrating cells in CLL lymph node (A) are all positive. Many cells in normal node (B) are also positive, particularly those in the germinal center (GC) of the follicles. (Original magnification, × 40.) CLL cells expanding the white pulp (WP) of the spleen (C) are also uniformly positive. In contrast, in normal spleen (D), the different layers of the white pulp show various degrees of positivity that was stronger in the marginal zone and follicle centers. (Original magnification, × 10.)