(A and B) Proliferating Lgr5+ stem cells marked by EdU in the distal colon from AhR WT (GT) and KO (HGT) mice. Arrowhead and star symbols denote proliferating stem cells (GFP+EdU+) and static stem cells (GFP+EdU-), respectively, during a 2 h EdU pulse, n=3 per treatment. 