LGR5 and adenoma: To test whether stem cell-specific Brg1 loss could attenuate Wnt-driven adenoma formation we intercrossed mice expressing the GFP-IRES-CreERT2 knock-in allele under control of the Lgr5 promoter (further abbreviated as Lgr5-GFP-CreERT2) [23] with animals bearing targeted Apc and Brg1 alleles.