Further studies of adenoma formation in mice observed a caudal shift of the tumour location from small intestine towards colon after introducing an additional knockout of Smad3 in the ApcMin/+Smad3−/− mouse or a heterozygous mutation of Cdx2 in the Apc+/Δ716Cdx2+/− mouse [28, 29]. This evidence concerns the gene SMAD3 and adenoma.