Cdx and Hox genes differentially regulate posterior axial growth in mammalian embryos.Concerted involvement of Cdx/Hox genes and Wnt signaling in morphogenesis of the caudal neural tube and cloacal derivatives from the posterior growth zoneCdx2 determines the fate of postnatal intestinal endodermCdx2 contributes to the expansion of the early primordial germ cell population in the mouseEvolutionarily conserved requirement of Cdx for post-occipital tissue emergence