ZEB1 (zinc-finger E-box-binding homeobox 1), also known as TCF8 (transcription factor 8), is a delta-EF1/ZFH-1 C2H2-type zinc finger that bears seven C2H2-type zinc fingers and one homeobox DNA-binding domain. ZEB1 is a transcriptional repressor of interleukin-2 (IL-2). Mutations in the ZEB1 gene are associated with posterior corneal dystrophy type 3 (PPC3) a rare disorder characterized by metaplasia and overgrowth of corneal endothelial cells. ZEB1 appears to be critical to epithelial to mesenchymal transitions (EMT) during development and cancer metastasis. As a transcription factor involved in EMT, ZEB1 promotes EMT by repressing genes associated with the epithelial phenotype and activates genes associated with the mesenchymal phenotype.