What is "cdx"

The Cdx gene family, also called caudal genes, are a group of genes found in many animal genomes. Cdx genes contain a homeobox DNA sequence and code for proteins that act as transcription factors. The gene after which the gene family is named (the founding member) is the caudal or cad gene of the fruitfly Drosophila melanogaster. The human genome has three Cdx genes, called CDX1, CDX2 and CDX4. The zebrafish has no cdx2 gene, but two copies of cdx1 and one copy of cdx4. The Cdx gene in the nematode Caenorhabditis elegans is called pal-1. In many animals, the Cdx gene is part of a ParaHox gene cluster.