APC and neoplasm: 2, 5 and 6), we observed co-expression of Lgr5 and another intestinal stem cell marker, Tnfrsf19. As molecular basis of tumorigenesis in Apc+/Min mice is the abnormal activation of the canonical Wnt signaling pathway mediated by β-catenin (reviewed in [100]), we expected tumor cells to express Wnt signaling target genes.