Xenobiotic receptor meets NF-kappaB, a collision in the small bowel.

It has long been appreciated that inflammation and infection reduce drug metabolism and that exposure to drug metabolism-inducing xenobiotics can impair immune function. A new study reveals the mutual repression between the xenobiotic nuclear receptor PXR/SXR and NF-kappaB signaling pathways, providing a molecular mechanism linking xenobiotic metabolism and inflammation (Zhou et al.,).