APC and neoplasm: While the Apc-Cdkn1a network was generated using tumor-specific ApcMin/+ data – a model harboring a number of background genetic lesions [41] – the intestinal tissue obtained from the Apc1638N+/− and Cdkn1a−/− mice at 3 months of age is relatively polyp free, thus allowing us to gauge the effect of a single genetic perturbation on the pre-neoplastic epithelium.