At the same time, mutations in genes impairing oxidative phosphorylation causing defects in mitochondrial energy metabolism have been reported for a restricted subset of tumours such as succinate dehydrogenase in hereditary PPGL, RCC and gastrointestinal stromal tumours38, fumarate hydratase in hereditary leiomyomatosis and RCC39 and isocitrate dehydrogenase 1 (IDH1) and IDH2 in secondary glioblastomas and acute myeloid leukaemia40,41. This evidence concerns the gene IDH2 and renal cell carcinoma.