FH and neoplasm: FH is a critical enzyme utilized in the tricarboxylic acid cycle, otherwise known as the Krebs cycle, where it converts fumarate to malate [3]. Sporadic or germline mutations cause fumarate accumulation, which is suspected to cause tumor formation by stabilizing hypoxia-inducible factors (HIF), such as HIF-1⍺ and HIF-2⍺, which promote angiogenesis, proliferation, and survival, via the inhibition of prolyl hydroxylases [3].