Zinc-finger transcription repressor factor (PubMed:15225875, PubMed:23319585). Plays a critical role in maintaining the identity of epithelial lineages by suppressing epithelial-to mesenchymal transition (EMT) mainly through the repression of ZEB1, an EMT inducer (PubMed:24735878, PubMed:24735879). Positively regulates neuronal differentiation (PubMed:16423343, PubMed:23319585). Suppresses cell cycling and terminal differentiation of keratinocytes by directly repressing MYC and NOTCH1 (By similarity). Important for the correct development of primordial germ cells in embryos (PubMed:28059165). Expressed highly in testis, specifically in spermatocytes. Expressed also in skin and at lower levels in the ovary. Expressed during early-mid embryogenesis, particularly in the inner cell mass at 3.5 dpc, in epiblast at 6.5 dpc, and at later stages in ectodermally derived tissues such as the rostral surface ectoderm (PubMed:16423343). Expressed in embryonic stem cells, epiblasts of 6.4 dpc embryos and primordial germ cells (PGCs) (PubMed:28059165). High expression levels in PGCs of 8.5 dpc embryos decrease over embryogenesis (PubMed:28059165). Up-regulated during prepupertal testis development (PubMed:15225875). Down-regulated during embryonic stem cell neural differentiation and up-regulated by BMP4. Mutant embryos are small and die at 9.5 dpc-10.5 dpc with an open neural tube, impaired extra-embryonic and embryonic vascularization, abnormal cardiogenesis and placental defects (PubMed:16423343). Reduced number of primordial germ cells in 8.0 dpc embryos (PubMed:28059165). Major form in the testis. Belongs to the krueppel C2H2-type zinc-finger protein family.