NKX6.1 (NK homeobox factor 6.1; also NKX6A) is a 39-46 kDa member of the homeodomain family of transcription factors. It is expressed in embryonic ventral neural tube where it drives neural progenitors to form motoneurons and V2-type interneurons. It is also expressed in both fetal and neonatal pancreas where it promotes a beta-cell phenotype. NKX6.1 exhibits both transcriptional gene repression (NKX6.2 and Dbx2) and activation (cyclin A2 and B1). When overexpressed, it induces beta-cell mitosis. Human NKX6.1 is 367 amino acids (aa) in length. It contains a repressor region composed of Pro and Ala (aa 136-173), a DNA binding homeobox (aa 236-295) and a Glu:Asp-rich transactivation domain (aa 305-337). Over aa 1-120, human NKX6.1 shares 96% aa identity with mouse NKX6.1.