Previously, we used chitosan as a delivery vector to repress posttranscriptional vascular endothelial growth factor (VEGF) and zinc finger E-box binding homeobox (ZEB) expression, which resulted in inhibition of tumor angiogenesis and epithelial-mesenchymal transition (EMT) of breast cancer cells [60,61,62]. The gene discussed is ZEB1; the disease is breast carcinoma.