APC and intestinal cancer: As previously [7] and here reported (Figure 2), in both human (colon) and mouse (upper GI tract) APC-driven intestinal cancers cells with intracellular β-catenin accumulation are clustered around the invasive front, thus suggesting that factors secreted from the stromal microenvironment are likely to play a role in the enhancement of Wnt signalling activity and the maintenance of stem-like cancer cells.