CDX is a caudal-related protein (Cdx) and member of the homeobox class of genes. Homeobox genes are a large family of transcription factors that play an important role in mesoderm development. CDX2 is one of three human homologs that functions in posterior structure development and intestinal epithelial development. CDX2 is a transactivator of several intestine-specific genes such as isomaltase, lactase, carbonic anhydrase, MUC2, and others. CDX2 may function as a tumor suppressor in the colon.