A well-known example is the oncometabolite 2-hydroxyglutarate (2HG), which can be used as a biomarker in isocitrate dehydrogenase (IDH) mutated acute myeloid leukemia (AML) and intrahepatic cholangiocarcinoma (ICC) patients [12, 13]. This evidence concerns the gene IDH3A and intrahepatic cholangiocarcinoma.