BM angiogenesis in patients with MM. Blood vessels were detected in 3-μm sections of 4% formalin and B5 solution-fixed, paraffin-embedded specimens obtained from patients with MM. Angiogenesis was measured as number of vessels per 400 × field and density of microvessels (capillaries and small venules) by staining endothelial cells using anti-CD34 monoclonal antibody, as described in “Materials and methods.” (A) BM angiogenesis in 2 representative patients: Ang-1–negative patient (i) and Ang-1–positive patient (ii) with MM. Original magnification, × 400. (B) Plots represent individual values, and bars represent mean levels.