To examine whether the Jdp2–AhR signaling axis was similar in the Kras-Trp53 cancer cell line and MEFs, we investigated the effects of Jdp2–AhR signaling on DRE2-dependent AhR promoter activity, DRE2/3-dependent recruitment of Jdp2 to the AhR promoter, and Jdp2-dependent ROS activity. The gene discussed is KRAS; the disease is cancer.