Furthermore, specific cancer-associated mutations, such as those found in nuclear-encoded mitochondrial enzymes like fumarate hydratase (FH) [9], succinate dehydrogenase (SDH) [9], and isocitrate dehydrogenase (IDH) [10], have been reported, leading to the definition of a distinct metabolic phenotype termed the “truncated TCA (tricarboxylic acid) cycle” [11]. This evidence concerns the gene FH and cancer.