Decreased Ptgs2 expression in intestinal polyps was also observed in ApcMin/+Clec7a−/− mice (Fig. 4c), and its expression was only detectable in CD45+ leukocytes, but not in EpCAM+ epithelial cells, in both polyps and non-polyp tissues (Fig. 4d). This evidence concerns the gene PTGS2 and intestinal polyp.