<p>The independent cloning of rodent EBF/Olf-1 and <taxon tax_id="7227">Drosophila melanogaster</taxon> Collier has defineda family of transcription factors, the Collier or COE family [<cite idref="PUB00006682"/>]. COE proteinshave various functions in different organisms. </p><p>In mouse, COE1 has a role in B-cell differentiation, and could also perform a role in neuronal differentiation. All three COE are expressed in immature olfactory neuronal precursors and mature olfactory neurons as well as in developping nervous system during embryogenesis.</p> <p>In Drosophila, Collier is involved in the formation of the embryonic somatic muscle DA3, in the patterning of the wing by mediating Hedgehog activity. It could also act as a second-level regulator in the patterning of embryonic head. This conserved region is located in a domain thought to be part of the DNA-binding region. The signature includes four conserved cysteines that could be part of a zinc-finger motif.</p>