LGR5 and adenoma: Immunohistochemical analysis of β-catenin expression in the small intestine of both Lgr5-GFP-CreERT2+Apcfl/fl and Lgr5-GFP-CreERT2+Apcfl/flBrgfl/fl mice revealed a mixture of micro and macro-adenomas with nuclear β-catenin at a range of time points (Figure 4B).