Moving from cell lines into primary CRC patient samples, the Medema group demonstrated that the LGR5+ fraction of tumours exhibited enhanced TCF/LEF activity (a measure of Wnt signalling output) and greater clonogenic capacity (both in vitro and in vivo), relative to the LGR5− fraction.49 Interestingly, the LGR5− fraction retained some clonogenic growth in vitro, and reacquired LGR5 positivity a week post sorting, suggesting a level of dependence on LGR5 for proliferation. The gene discussed is LGR5; the disease is colorectal carcinoma.