Sequence-specific transcription factor which is part of a developmental regulatory system that provides cells with specific positional identities on the anterior-posterior axis. Transcripts are present at E3.5 in the somitic cells, which give rise to the dorsal dermis by E5, and at E6.5-8.5 in the dorsal dermal and epidermal cells during the first stages of feather morphogenesis. Belongs to the Antp homeobox family.