Enables DNA-binding transcription activator activity, RNA polymerase II-specific and RNA polymerase II cis-regulatory region sequence-specific DNA binding activity. Acts upstream of or within several processes, including nervous system development; positive regulation of transcription by RNA polymerase II; and spleen development. Predicted to be active in nucleus. Is expressed in several structures, including alimentary system; branchial arch; ear; genitourinary system; and nervous system. Human ortholog(s) of this gene implicated in adult T-cell leukemia. Orthologous to human TLX1 (T cell leukemia homeobox 1). [provided by Alliance of Genome Resources, Apr 2022]