Predicted to enable DNA-binding transcription factor activity, RNA polymerase II-specific and RNA polymerase II cis-regulatory region sequence-specific DNA binding activity. Predicted to be involved in cell fate specification; lymphocyte migration; and regulation of transcription by RNA polymerase II. Predicted to act upstream of or within positive regulation of DNA-templated transcription. Predicted to be active in chromatin and nucleus. Is expressed in several structures, including digestive system; hematopoietic system; integument; kidney; and telencephalon. Human ortholog(s) of this gene implicated in asthma, nasal polyps, and aspirin intolerance and primary immunodeficiency disease. Orthologous to human TBX21 (T-box transcription factor 21).