(A) Schematic regimen for AOM/DSS-induction of colon tumorigenesis. At 8~12 wk of age, AhR WT (H, n=10) and KO (HV, n=10) mice were treated with a single dose of AOM (10 mg/kg) by s.c injection, followed by 3 cycles of 2% DSS in the drinking water for 5 d. Mice were terminated 6 wk after the third cycle of DSS. 