Enables DNA-binding transcription factor activity and transcription cis-regulatory region binding activity. Involved in several processes, including epithelial cilium movement involved in determination of left/right asymmetry; positive regulation of type B pancreatic cell development; and type B pancreatic cell maturation. Acts upstream of or within determination of left/right symmetry. Located in chromatin. Part of transcription regulator complex. Is expressed in several structures, including central nervous system; genitourinary system; inner cell mass; pancreas; and sensory organ. Used to study visceral heterotaxy. Orthologous to human RFX3 (regulatory factor X3). [provided by Alliance of Genome Resources, Apr 2022]