ERBB2 and malignant colon neoplasm: It has been shown that in the human epidermal growth factor receptor 2 (HER2)/neu-overexpressing breast cancer cells, emodin suppresses the activity of HER-2/neu tyrosine kinase [55]; whereas, in colon cancer cells, emodin inhibits phosphorylation of vascular endothelial growth factor (VEGF) [56].