[3] Cdx proteins are key regulators of Hox genes.
The vertebrate Cdx proteins act upstream of Hox genes.
Cdx genes integrate the posteriorizing signals from retinoic acid and Wnt canonical pathways and relay this information to Hox promoters.
[4] Cdx2 expression begins at 3.5 days and is confined to the trophectoderm, being absent from the inner cell mass.
From 8.5 days, Cdx2 begins to be expressed in embryonic tissues, principally in the posterior part of the gut from its earliest formation.