CD55 and adenoma: This indicates that stromal remodelling with de-repression of a CD55(+) Wnt2b(+) stromal cell population is a shared feature in mouse and human lesions characterised by ectopic crypt formation, but is not seen in Wnt ligand-independent tubulovillous adenomas where constitutive epithelial wnt activation negates the need for environmental wnt ligand supply.