ZEB1 and neoplasm: However, upon further investigation of the tumor and its EMT status, the adjuvant-treated mice had tumors consisting predominantly of a Zeb1 low cells (more epithelial) rather than the Zeb1 high cells (more mesenchymal) that were injected, suggesting these tumors are dynamic [51] and undergo a mesenchymal to epithelial transition (MET) in vivo.