ZEB1 and cancer: As reported, epithelial-mesenchymal transition (EMT) and cancer stem cells are potential mechanisms contributing to VM formation (12), and some EMT-associated transcription factors, including Snail1, Nodal, zinc finger E-box binding homeobox 1 (ZEB1), ZEB2, and Twist1, may also be involved in VM formation (11, 13, 14).