Probably plays a role in the development of the brain and the sense organs. Can bind to the BCD target sequence (BTS): 5'-TCTAATCCC-3'. Brain: restricted regions of the developing rostral brain including the presumptive cerebral cortex and olfactory bulbs; expressed in the developing olfactory, auricolar and ocular systems, including the covering of the optic nerve. Embryo. Belongs to the paired homeobox family. Bicoid subfamily.