Our findings raise an important question related to the appearance of polyps in individuals in this affected family–could the appearance of a “second hit” involving a mutation in an oncogene, tumor suppressor or TGFβ pathway-related gene, work in combination with the germline APC gene mutation to give rise to polyps following the loss of immunosurveillance, which normally controls development and metastasis of cancers in both humans and mice? Here, TGFB1 is linked to neoplasm.