PET scanning of cancer patients injected intravenously with the radiolabeled glutamine analog, fluoro-glutamine (18F-FGln), showed high uptake into tumors harboring mutations in metabolic genes, including an RCC patient with a germline mutation in the SDHB gene, which encodes a subunit of succinate dehydrogenase [50]. Here, SDHB is linked to renal cell carcinoma.