CDX2 and polyp: On the basis of the results on polyp size and number, and considering that in both “normal” and adenomatous tissue the number of Y/Cdx2 positive cells after WT-BM transplantation progressively increased, we can state that WT-BM cells do not participate in the neoplastic progression but, on the contrary, reduce polyp formation and especially polyp growth with an almost “curative” effect.