Hox gene
Cdx genes play many roles during embryological development. This is particularly seen during the development of the body plan. Cdx genes are transcription factors that are influenced by signaling molecules such as Wnt, Retinoic acid and FGF (fibroblast growth factor) during body plan establishment in the developing embryo. Expression of Cdx is responsible for the control of the Hox gene family, which establishes the body plan posteriorly and anteriorly. The timed release of signaling molecules establishes the anterior/posterior axis formation and facilitates the regression of the primitive node. Hox genes area also critical for the proper orientation of the head, legs, arms, thorax and abdomen. Transfer of this information to Hox genes for positional development works directly through Cdx binding sites. Mutations to these binding sites have shown to ultimately prevent Hox gene expression and affect proper establishment of the body plan by preventing regulation of region-specific expression.