Immunohistochemical staining of CD31 and microvessel density (MVD). A: CD31 (200×). The blood vessels in tumor tissues were stained in yellow brown. a: control group; b: gemcitabine group; c: ginsenoside Rg3 group; d: combination group. B: MVD. MVD was determined by counting the number of microvessels per high-power field (hpf) in the section with an antibody reactive to CD31. ▫P < 0.05 vs control group; □P < 0.05 vs gemcitabine group; ■P < 0.05 vs ginsenoside Rg3 group.