Overexpression of Vav3 in human breast cancer. (A) The normal breast epithelial cells reveal negative immunoreactivity for Vav3 (200× magnification). Breast adenocarcinomas with well-differentiation (B), moderately differentiation(C), and poorly differentiation (D) show positive immunoreactivity (brown staining) for Vav3 in both nucleus and cytoplasm. Arrows indicate the breast epithelial and cancer cells. The microphotographs indicate nucleus feature of the breast epithelial and breast cancer cells (400× magnification). For moderately and poorly differentiation breast cancer cells, the nuclei are significantly enlarged and hyperchromatic with coarse clumping of chromatin, prominent nucleoli, and irregular nuclear membrane.