May be involved in head or eye development; development of the clypeolabrum and several head sensory organs. Expressed during early development of the head. First expressed in a band around the anterior end of stage 5 blastoderm embryo, at 93% to 85% egg length. By gastrula stage, site of expression shifts to the dorsal-anterior region. At stage 12, expression is found in the clypeolabrum, the stomodaeum, and in ectoderm dorsal to the future supraesophageal ganglion. Expressed during embryonic development. Belongs to the SIX/Sine oculis homeobox family.