(A) OVCAR5 cells were inoculated subcutaneously in nude mice, and tumor formation was monitored. At day 8 (arrow), mice were injected twice a week with 1 mg/kg of anti-EMP2 diabody KS83, KS49 and control diabody A10 or a vehicle control. Comparison by Student’s t test, * p<0.05. (B) At day 29, xenograft tumors were excised. Tumor histology was assessed by hemotoxylin and eosin staining (400× magnification). Insets represented the size of excised tumors (scale bar, mm). EMP2 expression was detected by (C) western blotting or (D) immunohistochemistry (200× magnification). Inset: negative staining with isotype control rabbit IgG.