Pa, Xenopus/Amphibian,-6 (Paired bo, Xenopus/Amphibian, protein) is a transcription factor with important functions in the development of the eye, nose, central nervous system and pancreas. Pa, Xenopus/Amphibian,-6 is required for the differentiation of pancreatic islet alpha cells, competes with PA, Xenopus/Amphibian,4 in binding to a common element in the glucagon, insulin and somatostatin promoters. Pa, Xenopus/Amphibian,-6 regulates specification of the ventral neuron subtypes by establishing the correct progenitor domains. Defects in Pa, Xenopus/Amphibian,-6 are associated with a number of diseases and abnormalities of the eye and optic nerve.