ARNT and hepatocellular carcinoma: To demonstrate a requirement for ARNT in 1,2-NQ- and 1,4-NQ-dependent induction of AhR-responsive gene expression, we examined the ability of 1,2-NQ and 1,4-NQ to induce AhR-dependent reporter gene expression in wild-type (Hepa1c1c7) and ARNT-deficient (BPRc1) mouse hepatoma cells [40].