Gap class segmentation protein that controls development of head structures. In embryo, expression of maternal transcript is highest in anterior region. Zygotic transcript is expressed in anterior region until the beginning of gastrulation and in posterior region until early gastrulation. After this, it is expressed in developing nervous system. Expressed maternally and zygotically. Expression of the maternal transcript decreases until embryonic stage 14, zygotic transcript is first detected at stage 11. Belongs to the hunchback C2H2-type zinc-finger protein family.