Involved in the development of the inner ear. Expressed in the developing forebrain and fins. Expressed during gastrulation, and shortly after gastrulation is expressed by presumptive precursor cells of the olfactory placodes, overlapping subsets of cells in the auditory vesicle, cells of the median fin fold, and cells of the visceral arches and their primordia. Belongs to the distal-less homeobox family.