Transcription factor which acts with the selector homeodomain proteins altering the regulation of downstream target genes such as wingless (wg), teashirt (tsh) and decapentaplegic (dpp), thus affecting segmental identity. Delimits the eye field and prevent inappropriate eye development. Required for proper localization of chordotonal organs within the peripheral nervous system. Interacts with Ubx and hth. Nuclear translocation requires interaction with hth. Prior to full germband retraction it is ubiquitously present, after germband retraction, mostly present in the anterior portion of the ventral nerve cord. Expressed both maternally and zygotically at all stages of development. Weak posterior-directed transformations in all 3 thoracic segments and in the anterior segments of the abdomen. Belongs to the TALE/PBX homeobox family.