DNA-binding regulatory protein implicated in early development. Involved in neuronal cell fate decision. Repressed directly or indirectly by the BX-C homeotic proteins. Initial expression in cellular blastoderm stage, then in ectodermal stripes during germband extension. Broad expression in the neuroectoderm followed by limitation to discrete subsets of CNS cells, and expression in specific PNS neurons and support cells. Expressed both maternally and zygotically. Belongs to the POU transcription factor family. Class-2 subfamily.