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 to sites in the 5'-flanking sequence of its coding region with various affinities. The consensus sequences of the high and low affinity binding sites are 5'-TAATGA[CG]-3' and 5'-CTAATTTT-3'. During development of the prepuberal testis high levels of HOXA4 transcripts were found at days 17, 24 and 30. The first day of HOXA4 expression was day 14. The activation of the HOXA4 gene in male germ cells seems to occur at the pachytene stage of meiotic prophase and its level of expression is stage-specific during embryogenesis. Overexpression results in abnormal gut development (megacolon). Belongs to the Antp homeobox family. Deformed subfamily.