Changes to metabolism disrupt cells' ability to differentiate. The mystery of how mutations in a gene called isocitrate dehydrogenase 1 (IDH1) cause brain cancer and leukaemia is beginning to be unravelled. Researchers have discovered that the mutations cause the production of an enzyme that can reconfigure on–off switches across the genome and stop cells from differentiating. The findings, published in three papers today in Nature1–3, could be used in the development of drugs for cancers with these mutations — a search that is already under way in many pharmaceutical companies. Some cancer patients could benefit from new treatments that target...