DUX3 belongs to the paired homeobox family and contains 2 homeobox DNA-binding domains. It expressed in hepatoma Hep3B cells. DUX genes are present in 3.3-kilobase elements, a tandem repeat family scattered in the genome found on the short arms of all acrocentric chromosomes as well as on several other chromosomes. May be functional despite lack of introns and of a poly(A) addition signal. Two different isoforms are known.