(from the article `evolution`) All animals have genes, which may be as few as 1, as in sponges, or as many as 38, as in humans and other mammals. genes are clustered in the ... Found on http://www.britannica.com/eb/a-z/h/76
Hox gene: One of a subgroup of homeobox genes that are found in clusters on the genes of vertebrates. These are referred to as Hox clusters in mammals. Hox clusters play a role in directing embryonic development. Found on http://www.medterms.com/script/main/art.asp?articlekey=23153