PTCH1 and irritable bowel syndrome: To help establish the role of the IBD in the development of extra intestinal malignancies—eliminating the impact of immunosuppressive drugs that may represent a confounding risk factor in IBD patients—we took advantage of the Ptch1+/− heterozygous knockout mice, a well-characterized MB model recapitulating many of the histological and molecular features of the human tumor counterpart [16].