The Homeobox as a Key for Understanding the Principles of the Genetic Control of Development -- Expression of Hox Genes in the Nervous System of Vertebrates -- The Hox Gene Network in Vertebrate Limb Development -- Evolution of Hox Gene Clusters -- Evolutionary Genomics of Hox Gene Clusters -- Chromatin and the Control of Hox Gene Expression -- Homeobox-Containing Genes in Limb Regeneration -- Hox Genes and Stem Cells -- Deregulation of the Hox Gene Network and Cancer. The study of Hox genes is crucial not only in exploring the enigma of homeosis but also in understanding normal development at the fundamental molecular level. "Hox Gene Expression" starts with the amazing discovery of the homeobox twenty-three years ago and follows the exciting path thereafter of a series of breakthroughs in Genetics, Development and Evolution. It deals with homeotic genes- their evolution, structure, normal and abnormal function. Researchers and graduate students in Biology and Medicine will benefit from this integrated overview of Hox gene activities.