Abnormal expression of human epidermal growth factor receptor 2 (Her-2) is seen in many common malignancies such as breast cancer, ovarian cancer, gastric cancer, colorectal cancer, etc. Her-2-positive tumor cells have higher growth-stimulating viability, which in turn causes rapid tumor growth and spread (Hung and Lau, 1999). The gene discussed is ERBB2; the disease is breast cancer.