LGR5 and adenoma: Barker et al. (2009) crossed Lgr5-EGFP-IRES-creERT2 knock-in mice with APCflox/flox mice to produce an Lgr5+ stem cell-specific knockout of APC, which resulted in the formation of macroscopic adenomas. In contrast, upon deletion of APC in TA or differentiated intestinal cells, these cells only formed microscopic adenomas. These data suggest that Lgr5+ stem cells, but not their differentiated progeny, are potential cells of origin of intestinal adenoma.