Enables DNA-binding transcription activator activity, RNA polymerase II-specific; RNA polymerase II core promoter sequence-specific DNA binding activity; and RNA polymerase II-specific DNA-binding transcription factor binding activity. Acts upstream of or within several processes, including branching involved in blood vessel morphogenesis; nervous system development; and neural crest cell migration. Located in nucleus. Is expressed in several structures, including 1st branchial arch; central nervous system; ear; embryo ectoderm; and reproductive system. Orthologous to human GBX2 (gastrulation brain homeobox 2). [provided by Alliance of Genome Resources, Apr 2022]