Researchers at the Max Planck Institute for Chemical Ecology in Jena, together with their colleagues at the Universities of Stockholm and Tokyo, report in a new study in PNAS that larvae of the cabbage white butterfly use two gut enzymes to effectively disarm the mustard oil bomb, the major chemical defense system of their host plants. Cabbage white butterflies appear to be able to target the various glucosinolates, defense compounds of cabbage and related plants, and render them harmless by a finely tuned use of their detoxification enzymes. Using genome editing techniques, the researchers were able to demonstrate the function of the individual enzymes and confirm their effectiveness.