A subgroup of homeobox genes, which play an important role in the developmental processes of a variety of multicellular organisms, Hox genes have been shown to play a critical role in vertebrate pattern formation. Hox genes can be thought of as general purpose control genes-that is, they are similar in many organisms and direct the same processes in a variety of organisms, from mouse, to fly, to human. * Provides researchers an overview and synthesis of the latest research findings and contemporary thought in the area.* Inclusion of chapters that discuss the evolutionary development of a wide variety of organisms.* Gives researchers and clinicians insight into how defective Hox genes trigger developmental abnormalities in embryos.