FH and glioma: However, mutations in TCA cycle enzymes, such as isocitrate dehydrogenase (IDH1/2), SDH, or fumarate hydratase (FH), generate oncometabolites like D-2-hydroxyglutarate (D-2HG), succinate, and fumarate, which disrupt epigenetic regulation and promote tumorigenesis in gliomas, AML, and renal cancers [10, 129–138].