homeotic genes control the body plan.
homeotic genes in organisms which display bilateral symmetry (including vertebrates ) are called Hox genes.
some genes contain a highly conserved sequence of 180bp, leading to the synthesis of a 60aa polypeptide. this conserved sequence is called the homeobox and the 60aa polypeptide is the homeodomain. it forms (part of) a transcription factor.
the homeobox is found in Hox genes. however, there are other homeobox-containing genes that are not Hox genes, which regulate expression of areas other than the body plan.