The Wnt signalling cascade is an ancient cell communication pathway operating in all animals, to control cell fates and body patterning during development and stem cell renewal in adult tissues. Its key effector is beta-catenin which, if incorrectly activated in human tissues, can drive cancer. Most notably, colorectal cancer is initiated in the intestinal epithelium by inactivating mutations of the APC tumour suppressor (a negative regulator of beta-catenin) or by activating mutations in beta-catenin. Activated beta-catenin is also a potent oncogene in many other cancers but is thought to be undruggable. Ultimately, our work was aimed at discovering new therapeutic targets for treating cancer.