Likely to play a regulatory role in the development of the ventral forebrain. May play a role in craniofacial patterning and morphogenesis. Heterodimer with MEIS1. Not expressed in the central nervous system. Expressed in a highly restricted region of the branchial arches. In later development, expressed in the developing middle and inner ear, teeth and whisker follicles. Belongs to the distal-less homeobox family.