Sequence-specific transcription factor which is part of a developmental regulatory system that provides cells with specific positional identities on the anterior-posterior axis. Binds the consensus region 5'-TTAAT[GT][GA]-3'. This homeotic protein controls development of the cells in the posterior thoracic and first abdominal segments. It activates the synthesis of the decapentaplegic (DPP) growth factor (By similarity). In the embryo, expression is seen in the epidermis, somatic and visceral mesoderm, and the peripheral and central nervous system. Belongs to the Antp homeobox family.