Fig 2: Evaluation of MVD in hepatocellular carcinoma tissues by CD31 staining. (A-D) The expression of CD31 was detected by immunofluorescence. (E) For the quantification of MVD, the slides were examined under ×100 magnification to identify areas containing the highest number of capillaries and small venules within the tumor. Images of 10 randomly selected fields (0.739 mm2/field) were captured at ×200 magnification to count microvessel-like structures consisting of endothelial cells that were stained with an anti-CD31 antibody. The average of the 10 areas was recorded as the MVD level. Every single green-stained cell and cell cluster, with or without the vessel lumen structure, was calculated as a blood vessel. The lowest MVD was found in the tumors from the VEGFR2-BMT mice. *P<0.01 vs. control group. MVD, microvessel density; BMT, bone marrow transplantation; VEGFR2, vascular endothelial growth factor receptor-2; CD, cluster of differentiation.