May have a role in development. May regulate its own transcription. May bind the bicoid consensus sequence TAATCC. Expressed in adult testis. Has a biphasic expression. Present in embryos in 8.5-10.5 dpc, reduced levels in 11.5 dpc and 13.5 dpc and absent in 15.5 dpc. Found in some adult tissues. Belongs to the paired homeobox family. Bicoid subfamily. Extended N-terminus.