The expression of Smad interacting protein 1 (SIP1, also known as ZEB2), a member of the ZEB group of transcription factors, plays a role in the impairment of colony formation and invasion of tumorigenic glioma cells through the regulation of E-cadherin and mesenchymal proteins, such as fibronectin and vimentin [157]. Here, ZEB1 is linked to central nervous system cancer.