LGR5 and neoplasm: Similarly, we used R26-tdTomato ApccKO/cKO Lgr5-EGFP-CreERT2 mice 6 weeks after Apc inactivation to isolate tdTomato+Trop2+ and tdTomato+Trop2− tumor cells and additionally a tdTomato-negative cell fraction that presumably contained differentiated Apc WT small intestinal epithelial cells (Figure 4D).