A clean house is a sign of a boring life. When more interesting or urgent matters arise, the housework has to wait. Similarly, when the body needs to fight infection, the liver's clean-up work is impaired. Chow et al. (page 2589) now show why: switching on virus-fighting factor interferon also switches off the liver's detoxification pathway.
Viral infection can cause metabolic disorders, including cholesterol and bone metabolism defects as well as Reye's syndrome, a defect in which aspirin becomes toxic because the liver fails to break it down. Liver detoxification is partly regulated by a transcription factor called retinoid X receptor (RXR), which turns on drug metabolism genes. But RXR is turned off by viral infection, Chow and colleagues now find.
RXR gets down-regulated by interferon regulatory factor 3 (IRF3), the same factor responsible for promoting virus-killing interferon expression as part of the primary...