Effect of ABZ, 2ME, and their combination on inhibition of tumor cell proliferation, angiogenesis, and apoptosis in HCT-116 subcutaneous tumor. Ki67-positive cells (brown) were counted and reported as the percentage of the total number of cells in proliferative phases in each field. CD31-positive vessel area (brown) were measured per high-power field (103 pixels). Cells underwent apoptosis (brown) were counted and reported as the percentage of total cells. (1) Vehicle control, (2) 25 mg/kg ABZ, (3) 50 mg/kg ABZ, (4) 25 mg/kg 2ME, (5) 25 mg/kg ABZ plus 2ME, and (6) 50 mg/kg ABZ plus 2ME. (*P < 0.05 and **P < 0.001 compared with single agents).